#include<fstream>
using namespace std;
fstream in,out;
char v[1050000];
int main(){
	long i,c=0,l=0,t=0;
	in.open("text.in",ios::in);
	out.open("text.out",ios::out);
	in.getline(v,1050000,'EOF');
	in.close();
	i=0;
	while(v[i]!=0){
		t=0;
		while((v[i]>='a'-0 && v[i]<='z'-0)||(v[i]>='A'-0 && v[i]<='Z'-0)){
			++t;
			++i;
		}
		if(t>0){
			l+=t;
			++c;
		}
		else ++i;
	}
	if(c>0)
		out<<(l/c);
	else
		out<<"0";
	out.close();
	return 0;
}