const cuv:set of char=['a'..'z','A'..'Z'];
var lc,lt,nr,nrc:longint;
    f:text;
    c:char;

procedure actualizez;
begin
if nr>0 then nrc:=nrc+1;
nr:=0;
lt:=lt+lc;
lc:=0;
end;

procedure citire;
begin
lc:=0;
lt:=0;
nr:=0;
assign(f,'text.in');reset(f);
while not eof(f) do begin
      while not eoln(f) do begin
            read(f,c);
            if c in cuv then begin
                             nr:=nr+1;
                             lc:=lc+1;
                             end
            else actualizez;
            end;
      readln(f);
      actualizez;
      end;
close(f);
end;

begin
citire;
assign(f,'text.out');rewrite(f);
writeln(f,lt div nrc);
close(f);
end.