View Compilation Error

0_0_9921607_10971.cpp: In function `int main()':
0_0_9921607_10971.cpp:5: error: `_int64' undeclared (first use this function)
0_0_9921607_10971.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_9921607_10971.cpp:5: error: expected `;' before "a"
0_0_9921607_10971.cpp:9: error: `a' undeclared (first use this function)
0_0_9921607_10971.cpp:9: error: `b' undeclared (first use this function)
0_0_9921607_10971.cpp:9: error: `c' undeclared (first use this function)
0_0_9921607_10971.cpp:12: error: `k' undeclared (first use this function)