#include "bits/stdc++.h" using namespace std; typedef long long ll; #define int ll typedef pair pii; #define rep(i,n) for(ll i=0;i<(ll)(n);i++) #define all(a) (a).begin(),(a).end() #define pb emplace_back const ll MOD = 1e9+7; signed main(){ int n,s,k; cin>>n>>s>>k; s -= n*(n-1)/2*k; static int dp[101][20001]; rep(i,101)rep(j,20001)dp[i][j] = 0; dp[0][0] = 1; for(int i=1;i<=n;i++){ for(int j=0;j<=s;j++){ int pay = 0; int remain = n-i+1; while(1){ if(j-pay>=0)(dp[i][j] += dp[i-1][j-pay])%=MOD; else break; pay += remain; int remain = n-i+1; } } } cout<