#include #include #include #include #include #include #include using namespace std; #define FOR(i,a,b) for (int i=(a);i<(b);i++) #define FORR(i,a,b) for (int i=(b)-1;i>=(a);i--) #define REP(i,n) for (int i=0;i<(n);i++) #define RREP(i,n) for (int i=(n)-1;i>=0;i--) #define pb push_back #define ALL(a) (a).begin(),(a).end() #define PI 3.1415926535 typedef long long ll; typedef pair P; //typedef complex C; const int MAX_N = 100; const int MAX_S = 20000; const ll mod = 1000000007; int N, S, K; ll dp[MAX_N][MAX_S + 1]; void input() { cin >> N >> S >> K; } void solve() { int s = 0; while (s <= S) { dp[0][s] = 1; s += N; } FOR(i, 1, N) { // FOR(j, min(K * (N - i), (N - i)), S + 1) { // dp[i][j] = dp[i - 1][j - K * (N - i)] + dp[i][j - (N - i)]; // dp[i][j] %= mod; // } REP(j, S + 1) { if (j - K * (N - i) >= 0) dp[i][j] += dp[i - 1][j - K * (N - i)]; if (j - (N - i) >= 0) dp[i][j] += dp[i][j - (N - i)]; dp[i][j] %= mod; } } cout << dp[N - 1][S] << endl; } int main() { input(); solve(); }