#include <iostream>
#include <cstring>
#include <fstream>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");
int main()
{ char a[1000],*p,sep[]=" !,-*?;";
int i,lungime=0,nrcuv=0;
f.get(a,1000);
p=strtok(a,sep);
while(p)
{
    nrcuv++;
    lungime=lungime+strlen(p);
    p=strtok(NULL,sep);
}
g<<lungime/nrcuv<<'\n';
    return 0;
}