#include<iostream>
using namespace std;
int mystrlen(char *buf,int N)
{
if(buf[0]==0||N==0)
return 0;
else if(N==1)
return 1;
int t=mystrlen(buf,N/2);
if(t<N/2)
return t;
else
return (t+mystrlen(buf+N/2,(N+1)/2));
}
int main()
{ char buf[]={'a','b','c','d','e','f',' ','x','y','z'};
int k;
k=mystrlen(buf,20);
cout<<k<<endl;
system("pause");
return 0;
}