Patient Rehabilitation

#include <bits/stdc++.h>
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define MOD (int) 1e9 + 7
#define all(x) begin(x), end(x)
typedef long long ll;
using namespace std;
template <typename T> // cin >> vector<T>
istream &operator>>(istream &istream, vector<T> &v) {
    for (auto &it : v)
        cin >> it;
    return istream;
}
template <typename T> // cout << vector<T>
ostream &operator<<(ostream &ostream, const vector<T> &c) {
    for (auto &it : c)
        cout << it << " ";
    return ostream;
}

void solve(void) 
{
    int n, x, y; cin >> n >> x >> y;
    vector<int> a(n); cin >> a;

    int ans = INT_MAX;
    for(int i = 0; i < y; i++) {
        int days = 1, j = i, cost = 0, start = i;
        while(j < n && days <= x) {
            cost += a[j];
            j += y;
            days++;
        }
        j -= y;
        if(days != x + 1) continue;
        ans = min(ans, cost);
        while(j + y < n) {
            cost -= a[start];
            cost += a[j + y];
            ans = min(ans, cost);
            j += y;
            start += y;
        }
    }
    cout << ans << '\n';
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    solve();
    return 0;
}