#include <fstream>
using namespace std;
ifstream fin ("text.in");
ofstream fout ("text.out");
int main()
{
    char ch;
    int cntl=0,s=0,cuv=0;
    while (fin.get(ch))
    {
      if((ch <= 'z' && ch >= 'a')|| (ch <='Z' && ch >= 'A'))
        cntl++;
      else
      {
        if(cntl > 0)
          cuv ++;
        s += cntl;
        cntl = 0;
      }
    }
    fout << s/cuv;
    return 0;
}