#include <iostream>
#include <fstream>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");
int nr,nrl,ok=0,nrlc,s,nrcuv;
char c;
int main()
{
    while (!f.eof())
    {
        f.get(c);
        if(c>='a' && c<='z' || c>='A' && c>='Z')
            nrlc++;
        else
        {
            s=s+nrlc;
            if(nrlc!=0)nrcuv++;
            nrlc=0;
        }
    }
    g<<s/nrcuv;
    return 0;
}