#include<iostream.h>
#include<fstream.h>
int main ()
{
	char c;
	long l,cuv,m;
	ifstream f("text.in");
	ofstream g("text.out");
	l=0;
	cuv=0;
	while(f.peek()!=EOF) {
		f.get(c);
		if(((c>='A')&&(c<='Z'))||((c>='a')&&(c<='z'))) {
			cuv++;
			while(((c>='A')&&(c<='Z'))||((c>='a')&&(c<='z'))) {
				l++;
				f.get(c);
			}
		}
	}
	g<<l/cuv;
	g.close();
	return 0;
}