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

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

int main()
{
	char *sir;
	sir=new char[40001];
	long n,s,i,num;
	n=0;s=0;
	while(!f.eof())
	{
		f.get(sir,40000);
		f.get();
		num=strlen(sir);
		if(isalpha(sir[0]))s++,n++;
		for(i=1;i<num;i++)
		{
			if(isalpha(sir[i]))s++;
			if(!isalpha(sir[i-1])&&isalpha(sir[i]))n++;
		}
	}

	if(n==0)g<<'0 \n';
	else g<<s/n<<'\n';
	f.close();
	g.close();
	return 0;
}