: over swap dup rot rot ;
: mod over over / * - ;

1

begin
  dup 50<
while
  dup 15 mod 0 = if
    69420 .
  else
    dup 3 mod 0 = if
      69 .
    else
      dup 3 mod 0 = if
        420 .
      else
        dup .
      fi 
    fi
  fi
  1+
repeat

ret