#include using namespace std; #define DEBUG(x) cerr<<#x<<": "< #define vl vector #define vii vector< vector > #define vll vector< vector > #define vs vector #define pii pair #define pis pair #define psi pair #define pll pair template pair operator+(const pair &s, const pair &t) { return pair(s.first + t.first, s.second + t.second); } template pair operator-(const pair &s, const pair &t) { return pair(s.first - t.first, s.second - t.second); } template ostream& operator<<(ostream& os, pair p) { os << "(" << p.first << ", " << p.second << ")"; return os; } #define X first #define Y second #define rep(i,n) for(int i=0;i<(int)(n);i++) #define rep1(i,n) for(int i=1;i<=(int)(n);i++) #define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--) #define rrep1(i,n) for(int i=(int)(n);i>0;i--) #define REP(i,a,b) for(int i=a;i bool chmax(T &a, const T &b) { if (a bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; } #define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end()); const ll inf = 1000000001; const ll INF = (ll)1e18 + 1; const long double pi = 3.1415926535897932384626433832795028841971L; #define Sp(p) cout<> n; int s, t; cin >> s >> t; s--; t--; vl a(n); rep (i, n) cin >> a[i]; vl b; for (int i = s; i < n; i++) b.push_back(a[i]); for (int i = 0; i < s; i++) b.push_back(a[i]); t = ((t - s) + n) % n; s = 0; swap(a, b); // DEBUG_VEC(a); ll ss = a[s], tt = a[t]; vl kouho; for (int i = 1; i < t; i++) { if (i < t - i) ss += a[i]; else if (i > t - i) tt += a[i]; else kouho.push_back(a[i]); } for (int i = t + 1; i < n; i++) { if (n - i < i - t) ss += a[i]; else if (n - i > i - t) tt += a[i]; else kouho.push_back(a[i]); } // DEBUG_VEC(kouho); if (kouho.size() == 1) ss += kouho[0]; else if (kouho.size() == 2) { sort(all(kouho)); ss += kouho.back(); tt += kouho[0]; } cout << ss - tt << endl; }