#include <fstream>
#include <cctype>
#include <cstdio>

using namespace std;

ifstream f("text.in");
ofstream g("text.out");


int main()
{
     char c; bool ok=false;
     unsigned long numcuv=0,numlit=0;

   while (!f.eof())
   {
       f.get(c);
    if (isalpha(c) && !ok) { numcuv++; numlit++; ok = true;  }
      else if (isalpha(c) && ok) {numlit++; }
         else ok = false;
    }
    g << numlit/numcuv;
    return 0;
}