View Compilation Error

0_0_38349407_14018.cpp: In function 'int main()':
0_0_38349407_14018.cpp:3:25: error: 'scanf' was not declared in this scope
     while(scanf("%d", &n) != EOF){
                         ^
0_0_38349407_14018.cpp:3:30: error: 'EOF' was not declared in this scope
     while(scanf("%d", &n) != EOF){
                              ^
0_0_38349407_14018.cpp:5:39: error: 'printf' was not declared in this scope
             printf("Score is error!\n");
                                       ^
0_0_38349407_14018.cpp:12:32: error: 'printf' was not declared in this scope
             case 9:printf("A\n"); break;
                                ^