#include using namespace std; #define fast_io ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL) #define pb push_back #define int long long #define ll long long #define ld long double #define rep(i, n) for (ll i=0; i=0; i--) #define mem(v, ha) memset(v, ha, sizeof(v)) #define all(a) a.begin(), a.end() #define allr(a) a.rbegin(), a.rend() #define CLOCK cerr << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n"; typedef vector vi; typedef vector> vvi; typedef vector> vpi; typedef vector vc; #define no cout << "No\n" #define yes cout << "Yes\n" #define mp make_pair #define ff first #define ss second const ll MOD = 1e9 + 7; //const ll mod = 998244353 ; const long double PI = 3.141592653589793238460; const int inf = (int)(1e9); template istream& operator>>(istream& in, vector& a) {for (auto &x : a) in >> x; return in;}; template ostream& operator<<(ostream& out, vector& a) {for (auto &x : a) out << x << ' '; return out;}; // auto sum=[&](int use, int y){return use+y;}; // function dfs=[&](int u) //void is the return type, int is the argument // sort(os.begin() , os.end() , [&](int i , int j) { // return str[i] < str[j]; // }); void solve() { int n, d, k; cin >> n >> d >> k; vector>dp(n + 1, vector(k + 2, 0)); dp[0][0] = 1; for (int i = 0; i < n; i++) { for (int j = 0; j <= k; j++) { int l = j + 1; int r = min(k, j + d); dp[i + 1][l] = (dp[i + 1][l] + dp[i][j]) % MOD; dp[i + 1][r + 1] = (dp[i + 1][r + 1] - dp[i][j] + MOD) % MOD; } for (int j = 0; j < k; j++) dp[i + 1][j + 1] = (dp[i + 1][j + 1] + dp[i + 1][j]) % MOD; } cout << dp[n][k] << '\n'; } int32_t main() { #ifndef ONLINE_JUDGE freopen("input.txt", "r", stdin); freopen("out.txt", "w", stdout); #endif fast_io; int T = 1; // cin >> T; while (T--) { solve(); } }