var c:char;
    b:boolean;
    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);
                      while not(eof(t)) do begin
                            while not(eoln(t)) do begin
                                  read(t,c);
                                  if eoln(t) then b:=true;
                                  if adevarat(c) then begin
                                     inc(leng);
                                     if b then inc(cuv);
                                     b:=false;
                                  end else b:=true;
                            end;
                            readln(t);
                      end;
 close(t);
 assign(t,'text.out'); rewrite(t);
                       if cuv<>0 then writeln(t,(leng div cuv)) else writeln(t,'0');
 close(t);
end.