#include <bits/stdc++.h>
#include "testlib.h"
using namespace std;

const int LIM = 1.1e7;
string s;

int main(int argc, char *argv[])
{
	registerValidation();

	s=inf.readWord(); inf.readEoln();
	ensuref(s.length()<=LIM, "The string is too long!");

	inf.readEof();

	for(char t : s)
		ensuref(islower(t), "The character is not in the charset");

	return 0;
}