#include using namespace std; using uint = unsigned int; using ll = long long; using ull = unsigned long long; template using V = vector; template using VV = V>; template using VVV = V>; template using VVVV = VV>; #define rep(i,n) for(ll i=0ll;i void chmin(T& t, const U& u) { if (t > u) t = u; } template void chmax(T& t, const U& u) { if (t < u) t = u; } // cin.tie(nullptr); // ios::sync_with_stdio(false); // cout << fixed << setprecision(20); void solve(){ ll n,s,k; cin >> n >> s >> k; s -= n*(n-1)/2*k; if(s < 0){ cout << 0 << endl; return; } V v(20010, 0); v[0] = 1; for(ll i=n; i>0; i--) for(ll j=i; j<20010;j++){ // cout << i << " " << j << " " << v[j] << endl; (v[j] += v[j-i])%=mod107; // cout << i << " " << j << " " << v[j] << endl; } cout << v[s] << endl; } int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); int t=1; // cin >> t; rep(i,t) solve(); }