if ($level[0]eq'+'){
			$value = $level[1] + $level[2] || $value;
		}
		elsif ($level[0]eq'-'){
                        $value = $level[1] - $level[2] || $value;
                }
		elsif ($level[0]eq'/'){
                        $value = $level[1] / $level[2] || $value;
                }
		elsif ($level[0]eq'*'){
                        $value = $level[1] * $level[2] || $value;
                }
		elsif ($level[0]eq'**'or$level[0]eq'^'){
                        $value = $level[1] ** $level[2] || $value;
                }
		elsif ($level[0]eq'%'){
                        $value = $level[1] % $level[2] || $value;
                }