class Solution 
{
public:
    string revolution(string s)
    {
        string ret;
        char pre =s[0];
        int count = 1;
        for(int i = 1; i < s.size(); i ++)
        {
            if(s[i]==pre)
            {
                count ++;
            }
            else
            {
                char tmp =  count+'0';
                ret = ret + tmp + pre;
                pre = s[i];
                count = 1;
            }
        }
        char tmp =  count+'0';
        ret = ret + tmp + pre;
        return   ret;
    }
    string countAndSay(int n) 
    {
        string ret = "1";
        int j = 1;
        while( j< n)
        {
            ret=revolution(ret);
            j++;
        }
        return ret;
    }
};