#include<fstream>
#include<string>
using namespace std;
int main()
{
ifstream in("text.in");
ofstream out("text.out");
string s;
long  car=0,cuv=0,i;
bool ok=0;
while(!in.eof())
{
  in>>s;
  for(i=0;i<s.size();i++)
  {
    if( (s[i]<='Z' && s[i]>='A' )|| ( s[i]<='z' && s[i]>='a')) 
    {
     ok=1;
	 car++;
    } 
	else 
	 if(ok)
	 {
	   ok=0;
	   cuv++;
	 }
  }
  if(ok) cuv++;
}
out<<car/cuv;
return 0;	
}