#include <bits/stdc++.h>

using namespace std;

ifstream f("text.in");
ofstream g("text.out");

long long lgmax,nrcuv,lgmedie;
char s[1000000001];
int main()
{
    while(f.getline(s,1000000001))
    {
    char *p=strtok(s," .,;/?-!_+=");
    while(p)
    {
        lgmax+=strlen(p);
        nrcuv+=1;
        p=strtok(NULL," .,;/?-!_+=");
    }
    }
    lgmedie=lgmax/nrcuv;
    g<<lgmedie;
    f.close();
    g.close();
    return 0;
}