#include<iostream.h>
#include<fstream.h>
#include<string.h>

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

int main()
{
	int nr;
	long sm;
	nr=0;
	sm=0;
	char *sir,*cuv;
	cuv=new char[201];
	sir=new char[40001];
	f.get(sir,40000);

	cuv=strtok(sir," -.,;:!1234567890()");
	while(cuv)
	{
		nr++;
		sm+=strlen(cuv);
		cuv=strtok(NULL," -.,;:!1234567890()");
	}
	g<<sm/nr;
	f.close();
	g.close();
	return 0;
}