#include <cstdio>
#include <cstring>
 
using namespace std;
 
char s[10000100];
 
int main() {
    freopen("text.in", "r", stdin);
    freopen("text.out", "w", stdout);
 
    int n = 0, let = 0, N;
    bool cuvon = false;
    
    //gets(s);

    while(gets(s) > 0) {  
    N = strlen(s);
    s[N] = '*';
    for(int i = 0; i <= N; ++ i) {
        if((s[i] >= 'A' && s[i] <= 'Z')||(s[i] >= 'a' && s[i] <= 'z')) {
            ++ let;
            cuvon = true;
        } else {
            if(cuvon) {
                cuvon = false;
                ++ n;
            }
        }
    }
    }
    printf("%d", let / n);
 
    return 0;
}