#include <bits/stdc++.h>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
int main()
{
    char a[1048575];
    int lgmax,nrcuv;
    char *p;
    fin.getline(a,1048580);
    p=strtok(a," ,.?!-/()[]{}");
    lgmax=nrcuv=0;
    while(p!=0)
    {
        lgmax+=strlen(p);
        nrcuv++;
        p=strtok(NULL," ,.?!-/()[]{}\\_<>");
    }
    fout<<lgmax/nrcuv<<"\n";
    fin.close();
    fout.close();
    return 0;
}