#include<bits//stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define req(i,n) for(int i = 1;i <=  n; i++)
#define rrep(i,n) for(ll i = n-1;i >= 0;i--)
#define ALL(obj) begin(obj), end(obj)
#define RALL(a) rbegin(a),rend(a)
typedef long long ll;
typedef long double ld;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const ll INF = 1e18;
ll mod = 1e9+7;
int main(){
   string s;cin >>s;
   sort(ALL(s));
   vector<int> al(13,0);
   for(char c: s){
       al[c-'a']++;
   }int f = 0;
   rep(i,13){
       if(al[i]==0) f++;
       if(al[i]>2) f +=2; 
   }if(f==0){
       for(char c:s) cout << c << endl;
   }else if(f==1){
       rep(i,13){
           if(al[i]==0) cout << (char)('a'+i) <<endl;
       }
   }else cout << "Impossible" <<endl;
}