#include <stdio.h>
#include <ctype.h>
int s=0, c;
bool sw;
char x;
int main()
{
freopen("text.in","r",stdin);
freopen("text.out","w",stdout);
x=fgetc(stdin);
while(!feof(stdin))
	{
   sw=1;
   while (!isalpha(x)&&!feof(stdin))
   	x=fgetc(stdin);
   while (isalpha(x)&&!feof(stdin))
   	{
      sw=0;
    	s++;
      x=fgetc(stdin);
      }
   if (sw==0)
   	c++;
   }
printf("%d", s/c);
return 0;
}
/*#include <stdio.h>

int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    char c;
    int i=0,nrl=0;
    c = fgetc(stdin);
    int ok;
    while(!feof(stdin))
        {ok=0;
         while(c>='a'&&c<='z' || c>='A'&&c<='Z')
            {
             nrl++;
             c = fgetc(stdin);
             ok=1;
             }
         if(ok==1)
            i++;
         c = fgetc(stdin);
         }


    printf("%ld",(nrl)/i);
    return 0;
}
*/