#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;
using ll = long long;


ll ownMax(vector<ll> &vec, ll tol, ll ig) {
    ll max = 0;
    for (int i = tol; i <= ig; i++)
    {
        if (max < vec[i]) {
            max = vec[i];
        }
    }
    return max;
    
}

bool goodForOwl(vector<ll >&trees, ll &visiblity, ll &index) {//nem megy túl a látótávolság sem az elején sem a végén
    if (index-visiblity>=0 && index+visiblity<trees.size()) {
        //nem úgy működik a max mint ahogy én akarom
        
        if (ownMax(trees, index-visiblity, index+visiblity)==trees[index]) {
            return true;
        }
        else {
            return false;
        }
        
    }
    else {
        if (index-visiblity>=0)//ez elején nem lóg túl de a végén igen
        {
            
            if (ownMax(trees, index-visiblity, trees.size()-1)==trees[index])
            {
                return true;
            }
            else {
                return false;
            }
        }
        else {
            
            if (ownMax(trees, 0, index+visiblity)==trees[index])
            {
                return true;
            }
            else {
                return false;
            }
        }
        
    }

    
    
}


int main() {
    ll numOfTrees, visibilityRange;
    cin >> numOfTrees >> visibilityRange;
    vector<ll> trees(numOfTrees);
    for (ll i = 0; i < numOfTrees; ++i) {
        cin >> trees[i];
    }
    for (ll i = 0; i < numOfTrees; ++i) {
        if (goodForOwl(trees, visibilityRange, i))
        {
            cout<<i+1;
            return 0;
        }
        
    }
    cout << -1;
}