#include<fstream.h>
#include<string.h>


ifstream in("text.in");
ofstream out("text.out");

int main(){
	char s[1000101];
	int ln,m=0,cuv=1,i,p;
	while(in.get(s,1000101)){
	in.get();
	ln=strlen(s);
	for(i=0;i<ln;i++)
		if(isalpha(s[i]))m++;
				
		else if(s[i]==' '&&isalpha(s[i+1]))cuv++;
	}
		
	if(m==0||cuv==0)
		out<<0;
	else out<<m/cuv;
	
}