#include <fstream>

using namespace std;

ifstream in("text.in");
ofstream out("text.out");

inline bool litera(char c)
{
	return (c>='a' && c<='z') || (c>='A' && c<='Z');
}

int main(){
	char a,b;
	int s=0,nr=0;
	in>>noskipws>>b;
	if(litera(b))
		++nr;
	while(in>>noskipws>>a){
		if(litera(a)){
			s++;
			if(!litera(b)){
				nr++;
			}
		}
		b=a;
	}
	out<<s/nr;
	in.close();
	out.close();
	return 0;
}