View Compilation Error

0_0_2753067_12674.cpp: In function `int main()':
0_0_2753067_12674.cpp:24: error: `_int64' undeclared (first use this function)
0_0_2753067_12674.cpp:24: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2753067_12674.cpp:24: error: expected `;' before "sum"
0_0_2753067_12674.cpp:26: error: `s' undeclared (first use this function)
0_0_2753067_12674.cpp:49: error: `sum' undeclared (first use this function)