#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;

int main()
{int ok=0,k=0,i,z=0;
char s;
   ifstream f("text.in");
   ofstream g("text.out");
while(f.get(s))
 {
     {if((s>='a'&&s<='z')||(s>='A'&&s<='Z'))
        k++;
     else
        {if(k)
         ok++;
         z=z+k;
         k=0;}
    }
 }
 g<<z/ok;
 f.close();
 g.close();


    return 0;
}