#include<fstream.h>
#include<string.h>
ifstream fin ("text.in");
ofstream fout ("text.out");
char s[1001];
int i, nrlit, nrcuv=1;
int main ()
{
	fin.get(s, 1001);
	for (i=1; i<strlen(s)-1; i++)
		if ((s[i]>='a' && s[i]<='z')||(s[i]>='A' && s[i]<='Z')) nrlit++;
			else if ((s[i+1]>='a' && s[i]<='z')||(s[i]>='A' && s[i]<='Z'))nrcuv++;
	fout<<"Lungimea medie este "<<nrlit/nrcuv;
	return 0;
}