#pragma GCC optimize ("O3")

#pragma GCC target ("sse4")

#include<bits/stdc++.h>

#include <algorithm>

#include <iostream>

#include <cstdio>

#include <queue>

#include <set>

#include <string>

#include <stdbool.h>

#include<ctime>

#include <cstring>

#define pub push_back

#define ll long long

#define max(a,b) ((a) > (b) ? (a) : (b))

#define min(a,b) ((a) < (b) ? (a) : (b))

#define BEND(c) (c).begin(),(c).end()

#define BEND2(c) (c).rbegin(),(c).rend()

#define fi first

#define se second

#define pi 3.1415926535897932384626

#define pfd(a) printf("%.15lf \n",a);

#define IOS ios_base::sync_with_stdio(false);cin.tie(0);

#define endl "\n"

#define MOD ( int)( 1e9 +7)

#define MAXN (ll) ((1000010))

#define ALPHABET_SIZE 26

//#define N (int)(1e5+10)

#define sag (sol|1)

#define sol (root<<1)

#define ort (bas+son)/2

#define INF (ll )1e18

#define int ll

using namespace std;

typedef vector<int> vi;

typedef vector<bool> vb;

typedef vector<vector<int>> vvi;

typedef vector<vector<pair<int, int>>> vvpi;

typedef vector<long long> vl;

typedef vector<pair<int, int>> vpi;

typedef vector<pair<long long, long long>> vpl;

typedef pair<int, int> pii;

typedef pair <ll, ll> pll;

typedef vector<vi> graph;

ll tt=1 , n , m , x , k , res= 0 , ans =0 ;

int p[MAXN];

ll fac[MAXN];

ll fast(ll a,ll b , ll mod )

{

ll res=1;

while(b)

{

if(b&1LL)

{

res*=a;

res%=mod;

}

b>>=1LL;

a*=a;

a%=mod;

}

return (res + mod)%mod;

}

void pre()

{

fac[0] = 1;

for (ll i = 1; i < 2e5; ++i)

fac[i] = (fac[i-1] * i) ;

}

int C(int a, int b)

{

if (a < b) return 0;

if (a == b) return 1;

int val = fac[a];

cout << val<<endl;;

val = (val * fast(fac[b], MOD-2 , MOD)) % MOD;

val = (val * fast(fac[a-b], MOD-2 , MOD)) % MOD;

return val;

}

void solve() {

int t;

cin >> n >> k >> t;

vector<int> d(107), d2(107);

d[0] = d2[0] = 1;

for(int i = 0 ; i < 107 ; i++) {

for (int j = 1; j <= k; j++) {

if (i + j >= 107) break;

d[i+j] = (d[i+j] + d[i]) % MOD;

}

}

for(int i = 0 ; i < 107 ; i++) {

for (int j = 1; j < t; j++) {

if (i + j >= 107) break;

d2[i+j] = (d2[i+j] + d2[i]) % MOD;

}

}

cout << ((d[n]-d2[n])%MOD+MOD)%MOD;

}

signed main(){

IOS;

//cin >> tt;

while (tt--){

solve();

}

//getchar(); getchar();

return 0;

}