#include <bits/stdc++.h>
using namespace std;
 ifstream fin ("text.in");
 ofstream fout("text.out");

int main()
{



    char c;
    int ok = 0, S = 0;
    int nrcuv = 0, nrl = 0;
while(fin.get(c))
 {

    if ( ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'))
        nrl++;
    else
    {
        if(nrl > 0)
            nrcuv++;
        S = S + nrl;
        nrl = 0;

    }


 }


 fout << S / nrcuv ;
 fout.close();
    return 0;
}