2059B.cpp

// coded by Cocane

#include<bits/stdc++.h>

#define ll long long
#define forn(i, n) for(int i = 0; i < n; i++)
#define for1(i, n) for(int i = 1; i <= n; i++)
#define foru(i, n) for(int i = n-1; i >= 0; i--)
#define fi first
#define se second
#define all(x) (x).begin(),(x).end()
#define allp(x) (x).begin(), (x).begin() + (x).size()/2, (x).rbegin()
#define pb push_back
#define ppb pop_back
#define read(a) for(auto &i: a) cin >> i
#define out(ans) cout<<ans<<endl
#define yn(a) cout<< (a ? "YES": "NO") <<endl

using namespace std;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef double dl;

void solve(){
        int n, k;
        cin >> n >> k;
        k /= 2;
        vi a(n);
        read(a);

        if(2 * k == n){
            for(int i = 1; i < n; i += 2){
                if(a[i] != (i + 1) / 2){
                    out((i + 1) / 2);
                    return;
                }
            }
            out(k + 1);
        } else {
            for(int i = 1; i <= n - 2 * k + 1; i++){
                if(a[i] != 1){
                    out(1);
                    return;
                }
            }
            out(2);
        }
}

int main(){
        ios::sync_with_stdio(false);
        cin.tie(NULL);

        int t;
        cin >> t;
        while(t--){
                solve();
        }
        return 0;
}