#include <bits/stdc++.h>

using namespace std;

char x[1001],*t,sep[]="\\ `1234567890-=~!@#$%^&*()_+[]{};':|,./<>?";

int lungime,cardinal;

int main()
{
    ifstream in ("text.in");
    ofstream out ("text.out");

    in.get(x,1000);

    t=strtok(x,sep);

    while( t )
    {
        lungime+=strlen( t );
        cardinal++;
        t=strtok(NULL,sep);
    }

    if( cardinal==0 )
        out<<0;
    else
        out<<lungime/cardinal;

    in.close();
    out.close();
    return 0;
}