View Compilation Error

0_0_31909749_14156.cpp: In function 'int main()':
0_0_31909749_14156.cpp:5:22: error: 'scanf' was not declared in this scope
 while(scanf("%d\n",&n)!=-1)
                      ^
0_0_31909749_14156.cpp:13:18: error: 'printf' was not declared in this scope
 printf("%d\n",sum);
                  ^