#include<fstream>
#include<string.h>
#define dmax 1048580
using namespace std;
ifstream in("text.in");
ofstream out("text.out");
char sir[dmax];
long int l,cuv,lit;
int main()
{	long int i;
	while(!in.eof())
	{	in.getline(sir,dmax,'\n');
		l=strlen(sir);
		for(i=0;i<l;i++)
		  if( ((sir[i]>='a')&&(sir[i]<='z')) || ((sir[i]>='A')&&(sir[i]<='Z')) )  
			{   lit++;  
				if( ((sir[i+1]<'a')||(sir[i+1]>'z')) && ((sir[i+1]<'A')||(sir[i+1]>'Z')) )  
					cuv++; 
			}         
	}	
	out<<lit/cuv;
	out.close();
	return 0;
}