#include<bits/stdc++.h> // #define SINGLE_INPUT #define ll long long #define ull unsigned long long #define N 500005 #define MOD 998244353 usingnamespace std;
voidsol(){ ll n, k; cin >> n >> k; vector<ll> a(n); for (ll& i:a) cin >> i; vector<pair<ll,ll>> p; if (a[0] != 1) p.emplace_back(a[0]-1, 1); for (int i=1; i<n; i++) { if (a[i] != 1+a[i-1]) p.emplace_back(a[i]-a[i-1]-1, a[i-1]+1); } p.emplace_back(1e15, a[n-1]+1); // for (auto [i,j]:p) { // cout << i << " " << j << endl; // } ll j = 0, c = 1, stp = 0; for (int i=0; i<k; i++) { while (p[j].first+stp < c) { stp += p[j].first; j++; } c = p[j].second + c-stp - 1; // if (c > a[n-1]) break; } cout << c << "\n"; }