#include "pch.h"
#include <iostream>
#include <string>
using namespace std;
int main() {
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	string str;
	while (getline(cin, str)) {
		for (int i = 0; i < str.length(); i++)
			if ((str[i] >= 'A' && str[i] <= 'Z') ||
				(str[i] >= 'a' && str[i] <= 'z') ||
				(str[i] == ' ') ||
				str[i] >= '0' && str[i] <= '9') {
				if (str[i] >= 'A' && str[i] <= 'Z') {
					char small_sy((int)str[i] + 32);
					cout << small_sy;
				}
				else
					cout << str[i];
			}
	}

	return 0;
}