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

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

	map<char, int> mp;
	for( int i = 0; i < S.size(); i++ ) {
		mp[ S[i] ]++;
	}

	int cnt1 = 0;
	int cnt2 = 0;
	for( auto e : mp ) {
		if( e.second == 1 ) cnt1++;
		if( e.second == 2 ) cnt2++;
	}

	if( cnt1 == 13 ) {
		for( int i = 0; i < S.size(); i++ ) cout << (char)('a' + i) << endl;
	}
	else if( cnt1 == 11 && cnt2 == 1 ) {
		for( int i = 0; i < S.size(); i++ ) if( mp.count( (char)('a' + i) ) == 0 ) cout << (char)('a' + i) << endl;
	}
	else cout << "Impossible" << endl;
}