#include <bits/stdc++.h>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;
typedef unsigned long long ull;


int main(){
  int N;
  cin >> N;
  int s, t;
  cin >> s >> t;
  s--; t--;
  vector<ll> v;
  rep(i,N){
    ll a;
    cin >> a;
    v.push_back(a);
  }
  vector<ll> w;
  rep(i,N){
    w.push_back(v[(s+i)%N]);
  }
  s = 0;
  t = (t+N-s)%N;

  ll X = v[s], Y = v[t];
  int rhs = t-1-s;
  int lhs = N-2-rhs;
  
  if(lhs%2==0 && rhs%2==0){
    {
      int p = s, q = t;
      while(true){
        p++; q--;
        if(p==(q+1)%N) break;
        X += v[p];
        Y += v[q];
      }
    }
    {
      int p = s, q = t;
      while(true){
        p=(p-1+N)%N;
        q=(q+1)%N;
        if(q==(p+1)%N) break;
        X += v[p];
        Y += v[q];
      }
    }
  }
  if(lhs%2==0 && rhs%2==1){
    {
      int p = s, q = t;
      while(true){
        p++; q--;
        X += v[p];
        if(p==q) break;
        Y += v[q];
      }
    }
    {
      int p = s, q = t;
      while(true){
        p=(p-1+N)%N;
        q=(q+1)%N;
        if(q==(p+1)%N) break;
        X += v[p];
        Y += v[q];
      }
    }
  }
  if(lhs%2==1 && rhs%2==0){
    {
      int p = s, q = t;
      while(true){
        p++; q--;
        if(p==(q+1)%N) break;
        X += v[p];
        Y += v[q];
      }
    }
    {
      int p = s, q = t;
      while(true){
        p=(p-1+N)%N;
        q=(q+1)%N;
        X += v[p];
        if(q==p) break;
        Y += v[q];
      }
    }
  }
  if(lhs%2==1 && rhs%2==1){
    int pp, qq;
    {
      int p = s, q = t;
      while(true){
        p++; q--;
        if(p==q) break;
        X += v[p];
        Y += v[q];
      }
      pp = p;
    }
    {
      int p = s, q = t;
      while(true){
        p=(p-1+N)%N;
        q=(q+1)%N;
        cout << p << " " << q << endl;
        if(p==q) break;
        X += v[p];
        Y += v[q];
      }
      qq = p;
    }
    
    if(pp > qq){
      X += v[pp];
      Y += v[qq];
    }else{
      X += v[qq];
      Y += v[pp];
    }
  }

  cout << X - Y << endl;
  
  return 0;
}