#include <iostream>
#include <string>
#include <fstream>

#define litera(c)(('a'<=c&&c<='z')||('A'<=c&&c<='Z'))
using namespace std;

int main()
{
long i, cuv=0, lit=0 ,len;
bool add=1;
string text;
freopen("text.in","r",stdin);
freopen("text.out","w",stdout);

while(getline(cin,text))
                        {
                        text="-"+text;
                        len=text.length();
                        for(i=0;i<len;i++)add=(litera(text[i])?0&(lit++,cuv+=add):1);
                        }
cout<<lit/cuv;
}