#include<fstream.h>
#include<string.h>
int main(){
char a[65535];
unsigned int s=0,k=0,i,y=0;
ifstream f("text.in");
ofstream g("text.out");
while(!f.eof())
	       {
	       f>>a;
	       for(i=0;i<strlen(a);i++)
		{
		if( (a[i]>47&&a[i]<58)||(a[i]>64&&a[i]<91)||(a[i]>96&&a[i]<123))
			{ while( (a[i]>47&&a[i]<58)||(a[i]>64&&a[i]<91)||(a[i]>96&&a[i]<123))
			       {k++;i++;}
			  y++;s+=k;
			}
		k=0;
		}

		}


g<<(int)s/y;
return 0;
}