#include<iostream>
#include<fstream>

using namespace std;

ifstream fin("text.in");
ofstream fout("text.out");

char n;
int lit,cuv,t,m;

int main()
{
    while(fin>>n)
    {
        if(('a'<=n && n<='z')||('A'<=n && n<='Z'))
            lit++;
        else
        {
            if(lit!=0)cuv++;
            t+=lit;
            lit=0;
        }
    }
    fout<<t/cuv;
    return 0;
}