View Compilation Error

0_0_31219561_12784.cpp: In function 'int main()':
0_0_31219561_12784.cpp:4:24: error: 'scanf' was not declared in this scope
     while(scanf("%d",&n)!=EOF)
                        ^
0_0_31219561_12784.cpp:4:27: error: 'EOF' was not declared in this scope
     while(scanf("%d",&n)!=EOF)
                           ^
0_0_31219561_12784.cpp:6:3: error: 'sum' was not declared in this scope
   sum=0;
   ^
0_0_31219561_12784.cpp:9:23: error: 'printf' was not declared in this scope
   printf("%lu\n\n",sum);
                       ^