#include <iostream>
#include <vector>

using namespace std;

int main()
{
    int n, d;
    cin >> n >> d;
    vector<int> F;
    for (int i = 0; i < n; i++) {
        int a;
        cin >> a;
        F.push_back(a);
    }
    for (int i = 0; i < d; i++) {
        F.push_back(0);
    }

    int maxi = 0, max = F[0], megoldas = -1, h=0, maxih = 0;
    bool kesz = false;
    do {
        maxih = maxi;
        for (int i = maxih+1; i <= maxih + d; i++) {
            if (F[i] > max) {
                max = F[i];
                maxi = i;
                h++;
            }
        }
        if (h == 0) {
            megoldas = maxi + 1;
            kesz = true;
        }
        h = 0;
    } while (!kesz);
    cout << megoldas;
}