#include <fstream>
#include <string>
#include <vector>

using namespace std;
ifstream in("text.in");
ofstream out("text.out");
int main()
{
 bool twowords=0;
 int sum=0,wordcount=0;
 vector <string> s;
 string word;
 while (in >> word)
    s.push_back(word);
 for (int i=0;i<s.size();i++)
 {
    for (int j=0;j<s[i].size();j++)
    {
    if (isalpha(s[i][j]))
        ++sum;
    if (s[i].size()>1 && s[i][j]=='-')
        twowords=1;

    }
    if (twowords)
    {
        wordcount = wordcount + 2;
        twowords=0;
    }
    else
        ++wordcount;

 }


 out << sum/wordcount;
}