#include<bits/stdc++.h>
using namespace std;
int ans=1;
string s;
int main(){
	cin>>s;
	for(int i=0;i<=s.size();i++){
		if(s[i]-'0'==s[i+1]-'0'){
			ans++;
		}else{
			cout<<ans<<s[i]-'0';
			ans=1;
		}
	}
	return 0;
}