View Compilation Error

0_0_25703252_22836.cpp: In function 'node pow(node, int)':
0_0_25703252_22836.cpp:54:16: error: no match for 'operator%' (operand types are 'node' and 'int')
         a=mul(a%2
                ^
0_0_25703252_22836.cpp:54:17: error: expected '}' at end of input
         a=mul(a%2
                 ^
0_0_25703252_22836.cpp:54:17: error: expected '}' at end of input