View Compilation Error

270069_0_23901.c: In function `main':
270069_0_23901.c:5: error: `_int64' undeclared (first use in this function)
270069_0_23901.c:5: error: (Each undeclared identifier is reported only once
270069_0_23901.c:5: error: for each function it appears in.)
270069_0_23901.c:5: error: syntax error before "a"
270069_0_23901.c:6: error: `a' undeclared (first use in this function)
270069_0_23901.c:6: error: `b' undeclared (first use in this function)
270069_0_23901.c:12: error: `total' undeclared (first use in this function)