#include<fstream>
using namespace std;
int main ()
{
	ifstream f("text.in");
	ofstream g("text.out");
	char c,ant;
	int total=0,nr=0;
	f.get(ant);
	if(ant>='A' && ant<='Z' || ant>='a' && ant<='z') total++;
	while(f.get(c))
	{
		if(c>='A' && c<='Z' || c>='a' && c<='z') total++;
		else if((c=='-' || c==' '||c=='!' ||c=='.' || c==',') && (ant>='A' && ant<='Z' || ant>='a' && ant<='z')) nr++;
		ant=c;
	}
	if(c>='A' && c<='Z' || c>='a' && c<='z') nr++;
	g<<total/nr;
	f.close();
	g.close();
	return 0;
}