View Compilation Error

0_0_26473515_15500.cpp: In function 'int main()':
0_0_26473515_15500.cpp:8:27: error: 'scanf' was not declared in this scope
  while (scanf("%d", &score))
                           ^
0_0_26473515_15500.cpp:11:16: error: 'printf' was not declared in this scope
    printf("A\n");
                ^
0_0_26473515_15500.cpp:13:16: error: 'printf' was not declared in this scope
    printf("B\n");
                ^
0_0_26473515_15500.cpp:15:16: error: 'printf' was not declared in this scope
    printf("C\n");
                ^
0_0_26473515_15500.cpp:17:16: error: 'printf' was not declared in this scope
    printf("D\n");
                ^
0_0_26473515_15500.cpp:19:16: error: 'printf' was not declared in this scope
    printf("E\n");
                ^
0_0_26473515_15500.cpp:21:30: error: 'printf' was not declared in this scope
    printf("Score is error!\n");
                              ^