EXHIBIT 10

CUSIP No. 09228F103

AGREEMENT CONCERNING JOINT FILING

OF SCHEDULE 13D

The undersigned agree as follows:

(i) each of them is individually eligible to use the Schedule 13D/A to which this Exhibit is attached, and such Schedule 13D/A is filed on behalf of each of them; and

(ii) each of them is responsible for the timely filing of such Schedule 13D/A and any amendments thereto, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is responsible for the completeness or accuracy of the information concerning the other person making the filing, unless such person knows or has reason to believe that such information is inaccurate.

This Agreement may be executed in any number of counterparts, each of which shall be deemed to be an original, but all of which, taken together, shall constitute one and the same instrument.

Dated: September 2, 2020

1

V. PREM WATSA
/s/ V. Prem Watsa
V. Prem Watsa
THE SECOND 810 HOLDCO LTD.
By:	/s/ V. Prem Watsa
	Name:	V. Prem Watsa
	Title:	President
THE SECOND 1109 HOLDCO LTD.
By:	/s/ V. Prem Watsa
	Name:	V. Prem Watsa
	Title:	President
THE SIXTY TWO INVESTMENT COMPANY LIMITED
By:	/s/ V. Prem Watsa
	Name:	V. Prem Watsa
	Title:	President
FFHL GROUP LTD.
By:	/s/ V. Prem Watsa
	Name:	V. Prem Watsa
	Title:	President
12002574 CANADA INC.
By:	/s/ V. Prem Watsa
	Name:	V. Prem Watsa
	Title:	President

2

FAIRFAX FINANCIAL HOLDINGS LIMITED
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Vice President and Chief Operating Officer
TIG INSURANCE (BARBADOS) LIMITED
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
FAIRFAX (US) INC.
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D

3

ODYSSEY US HOLDINGS INC.
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
ODYSSEY GROUP HOLDINGS, INC.
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
ODYSSEY REINSURANCE COMPANY
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
HUDSON INSURANCE COMPANY
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D

4

GREYSTONE INSURANCE COMPANY
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
CRUM & FORSTER HOLDINGS CORP.
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
UNITED STATES FIRE INSURANCE COMPANY
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
THE NORTH RIVER INSURANCE COMPANY
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D

5

NORTHBRIDGE FINANCIAL CORPORATION
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
FEDERATED INSURANCE COMPANY OF CANADA
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
NORTHBRIDGE GENERAL INSURANCE CORPORATION
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
CRC REINSURANCE LIMITED
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D

6

1102952 B.C. UNLIMITED LIABILITY COMPANY
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
ALLIED WORLD ASSURANCE COMPANY HOLDINGS, LTD
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
ALLIED WORLD ASSURANCE COMPANY HOLDINGS I, LTD
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
ALLIED WORLD ASSURANCE COMPANY, LTD
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D

7

ALLIED WORLD ASSURANCE HOLDINGS (IRELAND) LTD
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
ALLIED WORLD ASSURANCE HOLDINGS (U.S.) INC
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
ALLIED WORLD INSURANCE COMPANY
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
AW UNDERWRITERS INC.
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D

8

ALLIED WORLD SPECIALTY INSURANCE COMPANY
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
NEWLINE HOLDINGS UK LIMITED
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D
NEWLINE CORPORATE NAME LIMITED
By:	/s/ Peter Clarke
	Name:	Peter Clarke
	Title:	Attorney-in-Fact pursuant to Power of Attorney attached to this Schedule 13D

9

BRIT LIMITED
By:	/s/ Mark Allan
	Name:	Mark Allan
	Title:	Chief Financial Officer and Director
BRIT INSURANCE HOLDINGS LIMITED
By:	/s/ Mark Allan
	Name:	Mark Allan
	Title:	Director
BRIT UW LIMITED
By:	/s/ Mark Allan
	Name:	Mark Allan
	Title:	Director
BRIT REINSURANCE (BERMUDA) LIMITED
By:	/s/ Mark Allan
	Name:	Mark Allan
	Title:	Director

10

RIVERSTONE HOLDINGS LIMITED
By:	/s/ Nicholas C. Bentley
	Name:	Nicholas C. Bentley
	Title:	Chairman of the Board and Chief Executive Officer
RIVERSTONE INSURANCE (UK) LIMITED
By:	/s/ Luke R. Tanzer
	Name:	Luke R. Tanzer
	Title:	Managing Director

11

CONNEMARA REINSURANCE COMPANY LTD.
By:	/s/ Jean Cloutier
	Name:	Jean Cloutier
	Title:	Director
RIVERSTONE (BARBADOS) LTD.
By:	/s/ Janice Burke
	Name:	Janice Burke
	Title:	Vice President and General Manager
RESOLUTION GROUP REINSURANCE (BARBADOS) LIMITED
By:	/s/ Janice Burke
	Name:	Janice Burke
	Title:	Vice President and General Manager

12

NEWLINE INSURANCE COMPANY LIMITED
By:	/s/ Robert B. Kastner
	Name:	Robert B. Kastner
	Title:	Director

13

VERASSURE INSURANCE COMPANY
By:	/s/ Paula Sawyers
	Name:	Paula Sawyers
	Title:	Senior Vice President and General Counsel
ZENITH INSURANCE COMPANY
By:	/s/ Paula Sawyers
	Name:	Paula Sawyers
	Title:	Senior Vice President and General Counsel

14