#include<fstream>
#include<cstring>
using namespace std;
int ok,k,z;
int main()
{
    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;
}