#include <iostream>
#include <fstream>
#include <string>
using namespace std;
ifstream fi("text.in");
ofstream fo("text.out");
string s;
int main()
{
    int nr=0,l=0;
    while (fi>>s)
    {
        int ok=-1;
        for (int i=0;i<=s.size()-1;i++)
            if ((s[i]>='a'&&s[i]<='z')||(s[i]>='A'&&s[i]<='Z'))
                l++;
            else
                if ((s[i-1]>='a'&&s[i-1]<='z')||(s[i-1]>='A'&&s[i-1]<='Z')) {
                    nr++;
                    ok=i;
                }
        if (ok==-1)
            nr++;
    }
    fo<<l/nr;
}