#include<cstdio>
int main()
{
 freopen("text.in","r",stdin);
 freopen("text.out","w",stdout);
 int cuv=0,l=0;
 char c;
 while(!feof(stdin))
      {
       scanf("%c",&c);
       int q=0,pp=0;
       while((c>='A' && c<='Z') || (c>='a' && c<='z'))
            {
             scanf("%c",&c);
             if((c>='A' && c<='Z') || (c>='a' && c<='z'))
                q++;
             pp=1;
            }
       if(pp==1)
          {
           q++;
           l+=q;
           cuv++;
          }
      }
 printf("%d\n",l/cuv);
return 0;
}