#include <iostream>
#include <fstream>
#include <string.h>
#define VM 99999999

using namespace std;

ifstream f("text.in");
ofstream g("text.out");

char x;

int c=0,cuv=0,c1=0;

int main()
{
    while(f.get(x)){
        if (isalpha(x))
            ++c;
        else if (c>0){
               c1+=c;
               c=0;
               ++cuv;
             }
    }

    cout<<c1/cuv;

    return 0;
}