#include <iostream>

using namespace std;

int main()
{
    int n;
    int d;
    cin >> n;
    cin >> d;
    int fasor [n];
    for (int i = 0; i< n;i++){
        cin >> fasor[i];
    }
    bool rosszhely;
    for (int i = 0; i < n; i++){
        rosszhely=false;
        for (int j=i-d; j <= i+d;j++){
            if (j >= 0 && j<n){
            if (fasor[j] > fasor[i]){
                i=j-1;
                rosszhely = true;
                break;
                }
            }
        }
        if (rosszhely == false){
            cout << i+1;
            return 0;
        }
    }
    cout << "-1";
    return 0;
}