program teext;
var c:char;
    f,g:text;
    cuv,lt:word;
begin
assign (f,'text.in'); reset (f);
assign (g,'text.out'); rewrite (g);
lt:=0;
cuv:=0;
repeat repeat read (f,c);
              if (((c>=#65) and (c<=#90)) or ((c>=#97) and (c<=#122))) then lt:=lt+1;
       until ((c=#32) or (c=#26));
       cuv:=cuv+1;
until (eoln(f));
write (g,lt div cuv);
close (f);
close (g);
end.