var b,c:char;
    t:text;
    leng,cuv:int64;

function adevarat(c:char):boolean;
begin
 adevarat:=((ord(c)>64)and(ord(c)<91))or((ord(c)>96)and(ord(c)<123));
end;

begin
 assign(t,'text.in'); reset(t);
                      read(t,b);
                      while not(eof(t)) do begin
                            while not(eoln(t)) do begin
                                  read(t,c);
                                  if adevarat(c) then inc(leng)
                                                 else if adevarat(b) then inc(cuv);
                                  b:=c;
                            end;
                            readln(t);
                      end;
                      if adevarat(c) then inc(cuv);
 close(t);
 assign(t,'text.out'); rewrite(t);
                       writeln(t,(leng div cuv));
 close(t);
end.