View Compilation Error

0_0_9375969_12312.cpp: In function `int sum(int)':
0_0_9375969_12312.cpp:8: error: `s' undeclared (first use this function)
0_0_9375969_12312.cpp:8: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_9375969_12312.cpp:8: error: expected `;' before "um_i"
0_0_9375969_12312.cpp:8: error: `um_i' undeclared (first use this function)