View Compilation Error

0_0_23425644_26736.cpp: In function 'int main()':
0_0_23425644_26736.cpp:3:5: error: '__int64' was not declared in this scope
     __int64 i,n,sum;
     ^
0_0_23425644_26736.cpp:4:26: error: 'n' was not declared in this scope
     while(scanf("%I64d",&n)&&n>=0)
                          ^
0_0_23425644_26736.cpp:4:27: error: 'scanf' was not declared in this scope
     while(scanf("%I64d",&n)&&n>=0)
                           ^
0_0_23425644_26736.cpp:6:9: error: 'sum' was not declared in this scope
         sum=0;
         ^
0_0_23425644_26736.cpp:7:13: error: 'i' was not declared in this scope
         for(i=0;i<n;i++)
             ^
0_0_23425644_26736.cpp:14:29: error: 'printf' was not declared in this scope
         printf("%I64d\n",sum);
                             ^