#include <iostream>
#include <fstream>
#include <string.h>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
char s;
int main()
{
    int k1,k=0;
    k1=0;
    while(!fin.eof())
     {
         fin.get(s);
         if((s>=65&&s<=90)||(s>=97&&s<=122))
             k++;
             if(s==' '||s=='-'||s=='.'||s=='!'||s=='?'||s==':')
                if(k!=0)
                k1++;


     }
     fout<<k/(k1-1);
    return 0;
}