View Compilation Error

0_0_7121966_2668.cpp: In function `int main()':
0_0_7121966_2668.cpp:4: error: `_int64' undeclared (first use this function)
0_0_7121966_2668.cpp:4: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_7121966_2668.cpp:4: error: expected `;' before "a"
0_0_7121966_2668.cpp:7: error: `a' undeclared (first use this function)