#include <fstream.h>
#include <string.h>
ifstream fin("text.in");
ofstream fout("text.out");
int main()
{
	char linie[256];
	int n = 0 , nr = 0,m=0;
	while(!fin.eof())
	{
		fin.getline(linie,256);
		fin.get();
		char*p;
		p=strtok(linie," ,.!?-");
		while(p)
		{
			n = n+strlen(p);
			nr++;
			p = strtok(NULL,",.!?- ");
		}
		m++;
	}
	n=n+(m-1);
	fout << n/nr;
	return 0;
}