View Compilation Error

0_0_19353412_19954.cpp: In function 'int main()':
0_0_19353412_19954.cpp:5:5: error: '_int64' was not declared in this scope
     _int64 a,b,n,i,f[50]={0,1,2};
     ^
0_0_19353412_19954.cpp:6:10: error: 'n' was not declared in this scope
     cin>>n;
          ^
0_0_19353412_19954.cpp:7:9: error: 'i' was not declared in this scope
     for(i=3;i<50;i++)
         ^
0_0_19353412_19954.cpp:8:5: error: 'f' was not declared in this scope
     f[i]=f[i-1]+f[i-2];
     ^
0_0_19353412_19954.cpp:9:9: error: 'i' was not declared in this scope
     for(i=0;i<n;i++)
         ^
0_0_19353412_19954.cpp:11:14: error: 'a' was not declared in this scope
         cin>>a>>b;
              ^
0_0_19353412_19954.cpp:11:17: error: 'b' was not declared in this scope
         cin>>a>>b;
                 ^
0_0_19353412_19954.cpp:12:15: error: 'f' was not declared in this scope
         cout<<f[b-a]<<endl;
               ^