#include<fstream>
#include<string>
using namespace std;
char s[1048577];
long l,k,lc,i;
int main()
{
	ifstream f("text.in");ofstream g("text.out");
	f.getline(s,1048577);
	while(i<strlen(s))
	{
		while( (s[i]<='z' && s[i]>='a') || (s[i]<='Z' && s[i]>='A') )
		{
		 l++;
		 i++;
		}
		if(l)
		{
		 k++;
		  lc+=l;
	     l=0;
		}
	 i++;
	}
	if(k==0)g<<0;else
	g<<lc/k;
	f.close();g.close();
return 0;}