ARC091C AC

// Problem: E - LISDL
// Contest: AtCoder - AtCoder Regular Contest 091
// URL: https://atcoder.jp/contests/arc091/tasks/arc091_c
// Memory Limit: 256 MB
// Time Limit: 2000 ms
//
// Powered by CP Editor (https://cpeditor.org)

#include <assert.h>
#include <bits/stdc++.h>
using namespace std;
#define dbg(...) logger(#__VA_ARGS__, __VA_ARGS__)
template <typename... Args> void logger(string vars, Args &&... values)
{
    cerr << vars << " = ";
    string delim = "";
    (..., (cerr << delim << values, delim = ", "));
    cerr << endl;
}

template <class T> inline auto vv(int m) { return vector<vector<T>>(m, vector<T>(m)); }
template <class T> inline auto vv(int m, int n) { return vector<vector<T>>(m, vector<T>(n)); }
template <class T, T init> inline auto vv(int m) { return vector<vector<T>>(m, vector<T>(m, init)); }
template <class T, T init> inline auto vv(int m, int n) { return vector<vector<T>>(m, vector<T>(n, init)); }

template <class T> using mpq = priority_queue<T, vector<T>, greater<T>>;

using ll = long long;
using pii = pair<int, int>;
using vl = vector<ll>;
using vi = vector<int>;

int main(int argc, char **argv)
{
    ll n, a, b;
    cin >> n >> a >> b;
    if (a + b > n + 1 || a * b < n) {
        cout << -1 << endl;
        return 0;
    }
    vi ans;
    /*
    for (int i = b; i <= n; i += b) {
        for (int j = i; j > i - b; --j) {
            ans.push_back(j);
        }
    }
    if (ans.size() < n) {
        int rem = n - ans.size();
        for (int i = 0; i < rem; ++i) {
            ans.push_back(n - i);
        }
    }
    */
    int i = 0;
    for (a--; a >= 0; a--) {
        int sz = min(b, n - a);
        for (int j = i + sz; j > i; j--) {
            ans.push_back(j);
        }
        i += sz;
        n -= sz;
    }
    for (auto x : ans)
        cout << x << ' ';
    cout << endl;
    return 0;
};