#include <cmath>
#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <set>
#include <map>
#include <list>
#include <time.h>
#include <math.h>
#include <random>
#include <deque>
#include <queue>
#include <cassert>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <bitset>
#include <sstream>
#include <chrono>
#include <cstring>

using namespace std;

typedef long long ll;
const int mod = 1e9 + 7;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    string s;
    cin >> s;
    vector<int> c(26);
    for(int i = 0; i < s.size(); ++i){
        c[s[i] - 97]++;
    }
    int maxi = 0;
    int counter = 0;
    for(int i = 0; i < c.size(); ++i){
        maxi = max(maxi, c[i]);
    }
    for(int i = 0; i < c.size(); ++i){
        if(c[i] == maxi)
            ++counter;
    }
    if(maxi == 1){
        cout << counter << endl;
        for(int i = 0; i < c.size(); ++i){
            char a = 'a' + i;
            if(c[i])
                cout << a << endl;
        }
        return 0;
    }
    if(counter == 1){
        cout << 1 << endl;
        for(int i = 0; i < c.size(); ++i){
            for(int j = 0; j < c[i]; ++j){
                char a = 'a' + i;
                cout << a;
            }
        }
    }
    else if(counter == 2){
        bool flag = false;
        cout << 2 << endl;
        for(int i = 0; i < c.size(); ++i){
            if(c[i] < maxi){
                for(int j = 0; j < c[i]; ++j){
                    char a = 'a' + i;
                    cout << a;
                }
            }
            else{
                if(!flag){
                    for(int j = 0; j < c[i]; ++j){
                        char a = 'a' + i;
                        cout << a;
                    }
                    flag = true;
                }
                else{
                    cout << endl;
                    for(int j = 0; j < c[i]; ++j){
                        char a = 'a' + i;
                        cout << a;
                    }
                }
            }
        }
    }
    else{
        cout << 2 << endl;
        int st = 0;
        int nx = 0;
        for(int i = 0; i < c.size(); ++i){
            if(c[i] == maxi){
                st = i;
                break;
            }
        }
        for(int i = st + 1; i < c.size(); ++i){
            if(c[i] == maxi){
                nx = i;
                break;
            }
        }
        for(int i = 0; i < c.size(); ++i){
            if(c[i] < maxi){
                for(int j = 0; j < c[i]; ++j){
                    char a = 'a' + i;
                    cout << a;
                }
                c[i] = 0;
            }
            else if(c[i] == maxi && i == st){
                for(int j = 0; j < c[i]; ++j){
                    char a = 'a' + i;
                    cout << a;
                }
                c[i] = 0;
            }
            else if(c[i] == maxi && i != st && i != nx){
                for(int j = 0; j < c[i] - 1; ++j){
                    char a = 'a' + i;
                    cout << a;
                }
                c[i] = 1;
            }
        }
        cout << endl;
        for(int i = 0; i < c.size(); ++i){
            for(int j = 0; j < c[i]; ++j){
                char a = 'a' + i;
                cout << a;
            }
        }

    }

}