#include <iostream>
#include<fstream>
#include<string.h>
using namespace std;
fstream f("text.in",ios::in);
fstream g("text.out",ios::out);
 char a[20000040],*p;
 long long n=0,nr=0;
int main()
{
while(!f.eof())
{
    f.get(a,20000000);
    p=strtok(a," .,?;:'!@#$%^&*_+=-<>/*(){}][~`�$");
    if(!f.eof())
    while(p)
    {nr++;
    n+=strlen(p);
     p=strtok(NULL," .,?;:'!@#$%^&*_+=-<>/*(){}][~`�$");
}
}

g<<n/nr;
    return 0;
}