Being a Good Boy in Spring Festival

http://acm.hdu.edu.cn/showproblem.php?pid=1850

#include<iostream>
using namespace std;
char aa[102][22];
int mm[102];
main()
{
    int i,j,k,n,m,a,b,c,t;
    while(cin>>n && n) 
    {
        i=n;
        while(i--) 
        {
           cin>>mm[i];
           itoa(mm[i],aa[i],2);
         }
        for(j=mm[0],i=1;i<n;i++)
        {
            j=j^mm[i];          
        }
        itoa(j,aa[101],2);
        for(k=0,i=0;i<n;i++)
        {
              b=strlen(aa[i])-strlen(aa[101]);
              if(b>=0)
              {
                      if(aa[i][b]=='1') k++;
                     
              }               
        }   
        if(j==0) cout<<0<<endl;
        else cout<<k<<endl;
    }
}