#include <iostream>
#include <cstdio>
#include <cstring>
#define MAXSIZE 1 << 20
using namespace std;

int isLetter(char c)
{
    return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
}

char s[MAXSIZE];

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

    int total = 0;
    int nr = 0;

    cin.get(s, MAXSIZE, '\0');

    int start = -1;
    for(int i = 0; i < strlen(s); ++i)
    {
        if(isLetter(s[i]) && start == -1)
        {
            start = i;
        }
        if(!isLetter(s[i]) && start != -1)
        {
            ++nr;
            total += i - start;
            start = -1;
        }
    }

    cout << total / nr;
    return 0;
}