#include <fstream>
#include <ctype.h>
using namespace std;
int main(){ char x;
int cuv=0,lit=0,t=0;
ifstream f("text.in");
ofstream g("text.out");
while(!f.eof()){
f.get(x);
if(isalpha(x))
{lit++;
t=1;}
else
if((isprint(x) || isspace(x)) && t)
{cuv++;
t=0;}} 
g<<lit/cuv;
return 0;
}