#include <stdio.h>
#define Size 500000
char c[Size];
void Read()
{
	int x=0,pozi=0,pozf=0,sum=0,nc=0,ok=0;
	scanf("%c",&c[x]);
	while (c[x]!='\0')
	{
		if ((65<=c[x]&&c[x]<=90)|(97<=c[x]&&c[x]<=122))
		{
			ok++;
			pozf++;
		}
		else
		{
			if (ok)
			{
				sum+=pozf-pozi;
				nc++;
			}
			ok=0;
			pozi=pozf+1;
			pozf=pozi;
		}
		scanf("%c",&c[++x]);
	}
	printf("%d\n",sum/nc);
}
int main()
{
	freopen("text.in","r",stdin);
	freopen("text.out","w",stdout);
	Read();
}