非常简单

本人基本上不用万能头

---

# include <iostream>
using namespace std;
int main(){
    int pH;
    cin>>pH;
    if(pH<7){
        cout<<"Acidic";
    }
    else if(pH>7){
        cout<<"alkalinity";
    }
    else{
        cout<<"neutral";
    }
    
    return 0;
}