View Compilation Error

0_0_23113855_395.cpp: In function 'int main()':
0_0_23113855_395.cpp:5:31: error: 'scanf' was not declared in this scope
  while (scanf("%ld %ld", &a,&b) != EOF)
                               ^
0_0_23113855_395.cpp:5:36: error: 'EOF' was not declared in this scope
  while (scanf("%ld %ld", &a,&b) != EOF)
                                    ^
0_0_23113855_395.cpp:10:25: error: 'printf' was not declared in this scope
    printf("%ld\n", a + b);
                         ^