#include<fstream>

using namespace std;

ifstream f("text.in");
ofstream g("text.out");
int main(){
    int cuv=0,spt=0,litere=0;
    char a;
    while(f.get(a)){
        if(('a'<=a&&a<='z')||('A'<=a&&a<='Z'))litere++;
        else{if(litere)cuv++;
                    spt=spt+litere;
                    litere=0;}
    }
    g<<spt/cuv;
    f.close();
    g.close();
    return 0;
}