View Compilation Error

0_0_32327773_27634.cpp: In function 'int main()':
0_0_32327773_27634.cpp:4:29: error: 'scanf' was not declared in this scope
  while (scanf("%f%f", &m, &n) != EOF)
                             ^
0_0_32327773_27634.cpp:4:34: error: 'EOF' was not declared in this scope
  while (scanf("%f%f", &m, &n) != EOF)
                                  ^
0_0_32327773_27634.cpp:7:21: error: 'printf' was not declared in this scope
   printf("%.2f\n", x);
                     ^