#include<iostream>
#include<fstream>
#include<cstring>

using namespace std;
fstream fin("text.in",ios::in),fout("text.out",ios::out);
char x[1000],*p;
int main()
{
    int s=0,nrc=0;
    fin.getline(x,1000);
    p=strtok(x," ,-");

    while(p!=0)
    {
        nrc++;
        s+=strlen(p);
        p=strtok(0," ,.!-");
    }
    fout<<s/nrc;
    fin.close();
    fout.close();
    return 0;
}