#include <stdio.h>

int main()
{
	int clen = 0;	
	char c;
	int m = 0, n = 0;
	
	bool f = false;
	freopen("text.in","r",stdin);
	freopen("text.out","w",stdout);
	while (!feof(stdin))
	{
		scanf("%c",&c);
		if ( (c>='a' && c<='z') || (c>='A' && c<='Z'))
		{
			clen++;
			f  = true;
		}
		else
		{
			if (f)
			{
				f = false;
				m+=clen;
				clen = 0;
				n++;
			}
		}
	}
	if (n>0)
	{
		printf("%d",m/n);
	}
	else
	{
		printf("0");
	}
	return 0;
}