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