#include <stdio.h>
#include <ctype.h>
#include <string.h>
FILE *f=fopen ("text.in", "r");
FILE *g=fopen ("text.out", "w");
char a[1000000],*p,sep[75];
int k,nr,i;

int main() {
/*
while (!feof(f))
{
	fscanf (f, "%c", &x);
	if (isalpha(x))
		{ nr++;
		while (isalpha(x))
			{ k++; fscanf (f, "%c", &x); }
		}
}
fprintf (g, "%d", k/nr);
return 0; */

for (i=32;i<=126;i++)
	if ( (i<'a' || i>'z') && (i<'A' || i>'Z') )
		{ sep[k]=i; k++; }
fgets (a, 1000000, f);
k=0;
p=strtok (a, sep);
while (p)
{
	nr++;
	k+=strlen(p);
	p=strtok (NULL, sep);
}
fprintf (g, "%d", k/nr);
return 0;
}