View Compilation Error

0_0_15126201_12860.cpp: In function 'int main()':
0_0_15126201_12860.cpp:5:21: error: 'scanf' was not declared in this scope
  while(scanf("%f",&a)!=EOF)
                     ^
0_0_15126201_12860.cpp:5:24: error: 'EOF' was not declared in this scope
  while(scanf("%f",&a)!=EOF)
                        ^
0_0_15126201_12860.cpp:7:30: error: 'printf' was not declared in this scope
  printf("Score is error!\n\n");
                              ^
0_0_15126201_12860.cpp:10:16: error: 'printf' was not declared in this scope
  printf("A\n\n");
                ^
0_0_15126201_12860.cpp:13:16: error: 'printf' was not declared in this scope
  printf("B\n\n");
                ^
0_0_15126201_12860.cpp:16:16: error: 'printf' was not declared in this scope
  printf("C\n\n");
                ^
0_0_15126201_12860.cpp:19:16: error: 'printf' was not declared in this scope
  printf("D\n\n");
                ^
0_0_15126201_12860.cpp:21:16: error: 'printf' was not declared in this scope
  printf("E\n\n");
                ^