#define _USE_MATH_DEFINES #include using namespace std; #define FOR(i,m,n) for(int i=(m);i<(n);++i) #define REP(i,n) FOR(i,0,n) #define ALL(v) (v).begin(),(v).end() using ll = long long; const int INF = 0x3f3f3f3f; const ll LINF = 0x3f3f3f3f3f3f3f3fLL; const double EPS = 1e-8; const int MOD = 1000000007; // const int MOD = 998244353; const int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1}; const int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1}; template inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; } template inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; } struct IOSetup { IOSetup() { cin.tie(nullptr); ios_base::sync_with_stdio(false); cout << fixed << setprecision(20); } } iosetup; int main() { const int X = 16; int n, k; cin >> n >> k; vector a(n * 2); REP(i, n) cin >> a[i]; int lb = *min_element(ALL(a)), ub = *max_element(ALL(a)) + 1; FOR(i, n, n * 2) a[i] = a[i - n]; FOR(i, 1, n * 2) a[i] += a[i - 1]; while (ub - lb > 1) { int mid = (lb + ub) / 2; vector dp(X + 1, vector(n * 2, INF)); REP(i, n) dp[0][i] = lower_bound(ALL(a), (i > 0 ? a[i - 1] : 0) + mid) - a.begin() + 1; FOR(i, n, n * 2) dp[0][i] = n + dp[0][i - n]; REP(i, X) REP(j, n * 2) { if (dp[i][j] < n * 2) dp[i + 1][j] = dp[i][dp[i][j]]; } bool sp = false; REP(i, n) { int pos = i; REP(j, X + 1) { if (pos < n * 2 && (k >> j & 1)) pos = dp[j][pos]; } sp |= pos - i <= n; } (sp ? lb : ub) = mid; } cout << lb << '\n'; return 0; }