View Compilation Error

0_0_4579238_28044.cpp: In function `int main()':
0_0_4579238_28044.cpp:5: error: `_int64' undeclared (first use this function)
0_0_4579238_28044.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4579238_28044.cpp:5: error: expected `;' before "n"
0_0_4579238_28044.cpp:7: error: `n' undeclared (first use this function)
0_0_4579238_28044.cpp:7: error: `w' undeclared (first use this function)
0_0_4579238_28044.cpp:7: error: `d' undeclared (first use this function)
0_0_4579238_28044.cpp:7: error: `sum' undeclared (first use this function)