#include <iostream>
#include <string>
using namespace std;
 
char choice;
void M();
void C();
void Process();
 
void M(){
	cout <<"Multiplication\n";
}
void C(){
	cout << "Calculation\n";
}
void Process(){
	cout << "Make a choice\n"
		<< "C or M only\n";
	cin >> choice;
	while (strcmp(choice, "M")!=0) || (strcmp(choice, "C")!=0){
		cout << "ERROR Enter again";
	cin >> choice;
 
	}
	return;
}
 
 
void main () {
	Process();
	while (strcmp(choice, "M") == 0){
		M();
	}
	return;
	while (strcmp(choice, "C") == 0){
		C();
		return ;
	}
 
}