Uva 11192 - Group Reverse

#include<bits/stdc++.h>

using namespace std;

int main()
{
    ios_base::sync_with_stdio(0);

    int g;
    string s , res;

    while(cin >> g)
    {
        if(!g)break;
        cin.ignore();

        res = "";
        cin >> s;
        int len = s.size();
        int dvds = len / g;

        while(!s.empty())
        {
            reverse(s.begin(),s.begin()+dvds);
            //cout << s << " ";
            len = s.size();
            for(int i=0;i<len;i++)
            {
                if(i < dvds)
                {
                    res+=s[i];
                }

                else
                {
                    break;
                }
            }
            s.erase(0,dvds);
        }

        cout << res << "\n";
    }

    return 0;
}