View Compilation Error

0_0_35530342_12803.cpp: In function 'int main()':
0_0_35530342_12803.cpp:6:20: error: 'scanf' was not declared in this scope
 while(scanf("%d",&n)!=EOF){
                    ^
0_0_35530342_12803.cpp:6:23: error: 'EOF' was not declared in this scope
 while(scanf("%d",&n)!=EOF){
                       ^
0_0_35530342_12803.cpp:12:25: error: 'printf' was not declared in this scope
 printf("%d\n",(int)sum+1);
                         ^