#include <string>
#include <fstream>

using namespace std;

int n,i;
char s[10000], * pch;

int main()
{
	ifstream f("text.in");
	freopen("text.out","w",stdout);
	f.getline(s,sizeof(s));
	n=0;
	for(i=0; (int)i<=sizeof(s); i++)
		if((s[i]>='a'&&s[i]<='z')||(s[i]>='A'&&s[i]<='Z'))
			n++;
	i=0;
	pch=strtok(s," ,.-");
	while(pch != NULL)
	{
		i++;
		pch=strtok(NULL," ,.-");
	}
	printf("%d",n/i);
	return 0;
}