View Compilation Error

0_0_16515798_27552.cpp: In function 'int main()':
0_0_16515798_27552.cpp:4:1: error: '_int64' was not declared in this scope
 _int64 a[41]={0,1};
 ^
0_0_16515798_27552.cpp:6:1: error: 'a' was not declared in this scope
 a[m]=a[m-1]+a[m-2];
 ^
0_0_16515798_27552.cpp:9:18: error: 'a' was not declared in this scope
 printf("%I64d\n",a[m]);
                  ^