View Compilation Error

430347_0_0_19397.cpp: In function `int main()':
430347_0_0_19397.cpp:6: error: `_int64' undeclared (first use this function)
430347_0_0_19397.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
430347_0_0_19397.cpp:6: error: expected `;' before "sum"
430347_0_0_19397.cpp:8: error: `sum' undeclared (first use this function)