pragma solidity ^0.5.1;

contract contractA {
    function blah(int x, int y) public payable {}
}

contract contractB {
    function invokeContractA(address _addA) public  {
        contractA a = contractA(_addA);
        uint ValueToSend = 1234;
        a.blah.value(ValueToSend)(2, 3);
    }
}