#include<fstream.h>
#include<string.h>
#include<ctype.h>
void main()
{
	fstream f("text.in",ios::in);
	fstream g("text.out",ios::out);
	char s[1000000],sep[]=" -",*p,c,nrc=0,aux[1000000];
	int i,nr=0,nr2=0;
	while(f>>c)
	{
		f.get(s,1000000);
		strcpy(aux,s);
		s[0]=c;
		strcpy(s+1,aux);
		for(i=0;i<strlen(s);i++)
			if(ispunct(s[i])&&s[i]!='-')
				strcpy(s+i,s+i+1);
		p=strtok(s,sep);
		while(p)
		{
			nr+=strlen(p);
			strcpy(p,p+strlen(p));
			p=strtok(NULL,sep);
			nr2++;
		}
	}
	g<<nr/(nr2-1)<<endl;
	f.close();
	g.close();
}