#include "bits/stdc++.h"
using namespace std;
 
#define ll long long
 
#define       forn(i,n)              for(int i=0;i<n;i++)
#define          all(v)              v.begin(), v.end()
#define         rall(v)              v.rbegin(),v.rend()
 
#define            pb                push_back
#define          sz(a)               (int)a.size()

void solve()
{ 
    int len = 0, cnt = 0, ans = 0;
    char c;
    while(cin.get(c)){
        if(c >= 'a' && c <= 'z'){
            ++len;
        }else if(c >= 'A' && c <= 'Z'){
            ++len;
        }else{
            if(len){
                ans += len;
                ++cnt;
                len = 0;
            }
        }
    }
    if(len){
        ans += len;
        ++cnt;
    }
    if(cnt == 0)cout << 0;
    else cout << ans / cnt;
}   
 
int32_t main(){
    freopen("text.in", "r", stdin);
    freopen("text.out", "w", stdout);
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int t = 1;
    //cin >> t;
    while(t--)
    {
        solve();
    }
}