View Compilation Error

0_0_29226881_31568.cpp: In function 'int main()':
0_0_29226881_31568.cpp:4:2: error: '_int64' was not declared in this scope
  _int64 a[55]={0,1,1};
  ^
0_0_29226881_31568.cpp:10:4: error: 'a' was not declared in this scope
    a[i]=a[i-1]+a[i-2];
    ^
0_0_29226881_31568.cpp:13:20: error: 'a' was not declared in this scope
   printf("%I64d\n",a[n]);
                    ^