#include<fstream.h>
#include<string.h>
#include<ctype.h>
char s[250],*p;
int i,k1,k2;

int main()
{
 ifstream f("text.in");
 f.get(s,250);
 f.close();
 for(i=0;i<strlen(s);i++)
	if(!isalpha(s[i]))
		s[i]=' ';
 for(p=strtok(s," ");p;p=strtok(NULL," "))
	{
	 k1+=strlen(p);
	 k2++;
	}

 ofstream fout("text.out");
 fout<<k1/k2;
 fout.close();
 return 0;
}