#include <fstream>
#include<iostream>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
int main(){
    int cuv=0,spt=0,litere=0;
    char a;
    while(fin.get(a)){
        if(('a'<=a&&a<='z')||('A'<=a&&a<='Z'))litere++;
        else{if(litere)cuv++;
                    spt=spt+litere;
                    litere=0;}
    }
    fout<<spt/cuv;
    fin.close();
    fout.close();
    return 0;
}