#include<stdio.h>
#include<string.h>



int main()
{
	freopen("text.in","r",stdin);
	freopen("text.out","w",stdout);

	char s[256], sep[]=".,;!? -", *p;
	int i, litere=0, cuvinte=0, medie=1;

	p=strtok(s,sep);

	while(scanf("%s", &s)!=EOF)
	{
		if(strtok(s,sep))
			litere+=strlen(s);
			cuvinte++;


	}

	printf("%d", litere/cuvinte);
	return 0;
}