View Compilation Error

0_0_4665110_25738.c: In function `main':
0_0_4665110_25738.c:6: error: `_int64' undeclared (first use in this function)
0_0_4665110_25738.c:6: error: (Each undeclared identifier is reported only once
0_0_4665110_25738.c:6: error: for each function it appears in.)
0_0_4665110_25738.c:6: error: syntax error before "sum"
0_0_4665110_25738.c:10: error: `sum' undeclared (first use in this function)
0_0_4665110_25738.c:11: error: `sum1' undeclared (first use in this function)