View Compilation Error

0_0_17582094_27525.cpp: In function 'long long int sum(int)':
0_0_17582094_27525.cpp:44:12: error: expected primary-expression before '%' token
         x-=%
            ^
0_0_17582094_27525.cpp:44:12: error: expected primary-expression at end of input
0_0_17582094_27525.cpp:44:12: error: expected '}' at end of input
0_0_17582094_27525.cpp:44:12: error: expected '}' at end of input