#include<iostream.h>
#include <fstream.h>
#include  <string.h>
ifstream f ("text.in");
ofstream g("text.out");
char sir[1000];
int n,i,l,k;
int main ()
{f.get(sir,1000);
n=strlen(sir);
for (i=1;i<=n;i++)
{
	while ((sir[i]<'065' && sir[i]>'090') || (sir[i]<'097' && sir[i]>'122')) i++;
	while (sir[i]!=' ') {i++; l++; if(i>n) break; if(sir[i]=='-' || sir[i]==',' || sir[i]=='.' || sir[i]=='?' || sir[i]=='!') l--;}
	k++;
	if (sir[i]=='000') i=n;
}
g<<l/k;
f.close();
g.close();
return 0;
}