View Compilation Error

0_0_17935540_12296.cpp: In function 'int main()':
0_0_17935540_12296.cpp:47:17: error: invalid operands of types 'll {aka long long int}' and 'int(int)' to binary 'operator^'
             ans ^= sg[a];
                 ^
0_0_17935540_12296.cpp:47:17: error:   in evaluation of 'operator^=(ll {aka long long int}, int(int))'