how to use not operator in c++ code example

Example: Not c++

#include<iostream>
using namespace std;
int main(){
	int a;
    cin>>a;
    if(!((a >= 20 && a <= 30) || (a > 0 && a < 10))){
    	cout<<"Dentro!";
   	}
   	else{
		cout<<"Fuori!";
	}
}