Warning: 'transfer' is deprecated and scheduled for removal. Use 'call{value: <amount>}("")' instead.
  --> input.sol:10:3:
   |
10 | 		a.transfer(x);
   | 		^^^^^^^^^^

Warning: The BMC engine of the SMTChecker is deprecated and will be removed in a future release. Please use the CHC engine instead.

Warning: BMC: Condition is always true.
 --> input.sol:6:11:
  |
6 | 		require(x >= 0);
  | 		        ^^^^^^
Note: Callstack:
