#include <iostream>
#include <cstring>
using namespace std;
char letter[26] = {'a','b','c','d','e','f',
				   'g','h','i','j','k','l',
				   'm','n','o','p','q','r',
				   's','t','u','v','w','x',
				   'y','z'};
int lsum[26];
char letter_choose[1000];
string s;
int main()
{
	cin >> s;
	for (int i = 0; i < s.length(); i++)
	{
		for (int j = 0; j <= 25; j++)
		{
			if (s[i] == letter[j]) 
			{
				lsum[j]++;
				break;
			}
		}
	}
	for (int i = 0; i < s.length(); i++)
	{
		if (lsum[i] != 0) cout << letter[i] << lsum[i];
	}
	return 0;
}