#include <fstream>
#include <string.h>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
char q;
unsigned c,l,la;
int main()
{   while(fin.get(q))
        { if((q>='a')&&(q<='z')||(q>='A')&&(q<='Z'))
                l++;
          else 
			 if(l)
                {
                    la+=l;
                    l=0;
					c++;
                }
        }
         fout<<la/c;
    return 0;
}