#include <bits/stdc++.h>
#define DAU  ios::sync_with_stdio(false); fin.tie(0); fout.tie(0);
#define PLEC fin.close(); fout.close(); return 0;
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
char sir[1000000];
int curr, cnt, sum;
int main()
{
    DAU
    fin.get(sir, 999999);
    for (size_t i = 0; i < strlen(sir); ++i)
        if (('a' <= sir[i] && sir[i] <= 'z') || ('A' <= sir[i] && sir[i] <= 'Z'))
            ++curr;
        else if (curr)
            ++cnt, sum += curr, curr = 0;
    fout << sum / cnt;
	PLEC
}