A - Tiny Arithmetic Sequence

#include <iostream>
#include <cmath>
using namespace std;

int main() {
    int a,b,c,x;
    cin>>a>>b>>c;
    if(a>b){
       // swap(a,b);
        x=a;
        a=b;
        b=x;
    }
   if(b>c){
       x=b;
       b=c;
       c=x;
   }
       if(a>b){
        x=a;
        a=b;
        b=x;
    }
   if(b-a==c-b){
       cout<<"Yes";
   }
   else
   cout<<"No";

 return 0;
}