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