#include<fstream>
using namespace std;
long long s,nr,cr;
int main()
{char c;
ifstream in("text.in");
in.get(c);
while(!in.eof())
	{if(isalpha(c))
		s++,cr++;
	else
		if(cr>0)
			nr++,cr=0;
	in.get(c);
	}
in.close();
ofstream out("text.out");
out<<s/nr<<'\n';
out.close();
return 0;
}