Var f,g:text;
    a:char;
    b,c,d,e:integer;

Begin
assign(f, 'text.in');reset(f);
assign(g, 'text.out');rewrite(g);
d:=b;
while eof(f)=false do
  begin
    read(f, a);
    e:=b;
    case a of
      'a'..'z','A'..'Z':inc(b);
    end;
    if (e=b) and (d<>b) and (eof(f)=false) and (a<>',') and (a<>#13) then inc(c);
  end;
write(g, trunc(b/c));
close(f);
close(g);
End.