#include<stdio.h>
char c;
long int nl,nc,m,ntl;
int main()
{
	FILE *f=fopen("text.in","rb");
	while(fscanf(f,"%c",&c)!=EOF)
	{   if((('a'<=c)&&('z'>=c))||(('A'<=c)&&('Z'>=c))) nl++;
	    else if(nl){nc++;ntl+=nl;nl=0;}
	}
	fclose(f);
	f=fopen("text.out","w");
	if(nc)
	{ m=ntl/nc;
	  fprintf(f,"%ld\n",m);
	}
	else for(;;)//fprintf(f,"%ld\n",nl);
	fclose(f);
	return 0;
}