#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <algorithm>
#include <cmath>
#include <queue>
#include <stack>
#include <climits>
using namespace std;

using ll = long long;
const int MOD = 1e9 + 7;

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

    int n, k;
    cin >> n >> k;
    vector<int> nums(n);
    for(int i = 0; i < n; i++) {
        cin >> nums[i];
    }

    bool could = 0;
    for(int i = 0; i < n; i++) {
        bool can = 1;
        for(int j = (i-k >= 0) ? i-k : 0; j <= i+k && j < n; j++) {
            if(nums[i] < nums[j]) {
                can = 0;
                break;
            }
        }
        if(can) {
            could = 1;
            cout << i+1 << "\n";
            break;
        }
    }
    if(!could) cout << "-1\n";
}