#include <fstream>
#include <cstring>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");
char s[100],*p,ss[100];
int l=0,nr=0;
int main ()
{
    int i;
    f.get(s,100);
    f.get();
    for(i=1;i<strlen(s);i++)
        if(('a'<=s[i]&& s[i]>='z')||('A'<=s[i]&&s[i]>'Z'))
           l++;
    strcpy(ss,s);
    p=strtok(ss," ,.-!?");
    while (p!=NULL)
    {
        nr++;
        p=strtok(NULL," ,.-!?");
    }
    g<<l/nr;
    g.close();
    return 0;
}