#include <iostream>
#include <limits.h>
#include <cmath>
#include <string>
#include <stdio.h>
#include <algorithm>
#include <stdlib.h>
#include <vector>
#include <stack>
#include <map>
#include <fstream>
#include <list>
#include <queue>
#include <iomanip>
#include <deque>
#include <set>
#include <cstdio>
#include <cstring>

using namespace std;

char s[10000100];

int main()
{
    freopen("text.in", "r", stdin);
    freopen("text.out", "w", stdout);

    int cuvinte = 0;
    int litere = 0;
    bool ok = false;

    while(gets(s) > 0)
    {
        int q = strlen(s);
        s[q] = '#';

        for(int i = 0; i <= q; i++)
            if((s[i] >= 'A' && s[i] <= 'Z')||(s[i] >= 'a' && s[i] <= 'z'))
                {
                        litere++;
                        ok = true;
                }
            else
                if (ok)
                    {
                        cuvinte ++;
                        ok = false;
                    }
    }

     printf("%d", litere/cuvinte);

    return 0;
}