#include<bits/stdc++.h>
using namespace std;
int main()
{
    char a[255];
    int b[30]={0};
    cin>>a;
    int i=0,n=0;
    n=strlen(a);
    for(i=0;i<n-1;i++){
        b[a[i]-'a']++;
    }
    for(i=0;i<26;i++){
        if(b[i]>0)
            cout<<b[i];
        if(b[i]>0)
            cout<<char(i+'a');
        if(b[i]==1){
            cout<<char(i+'a');
        }
    }

    return 0;
}
/**************************************************************
	Problem: 1103
	User: luyanchen
	Language: C++
	Result: Wrong Answer
****************************************************************/