#include<stdio.h>
#include<string.h>
char a[10000];
unsigned long n,l,c,l1,i;
int main()
{
FILE *f=fopen("text.in","r");
FILE *g=fopen("text.out","w");
while(f)
	{
	fgets(a,10000,f);
	n=strlen(a);
	while(i<n)
		{
		l1=l;
		while(i<n && (a[i]>='a' && a[i]<='z') || (a[i]>='A' && a[i]<='Z'))
			{
			l++;
			i++;
			}
		if(l>l1)
			c++;
		i++;
		}
	}
if(c>0)
	fprintf(g,"%d\n",l/c);
else
	fprintf(g,"%d\n",0);

return 0;
}