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

int main()
{
	string S;
	cin >> S;

	char ans[8];
	for( int i = 0; i < S.size(); i++ ) {
		if( S[i] - 'a' != i ) {
			sprintf( ans, "%cto%c", (char)(i + 'a'), S[i] );
			break;
		}
	}

	cout << ans << endl;
}