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#include <bits/stdc++.h>
using namespace std;
using LL = long long int;
LL MOD = 1e9 + 7;
class Solution {
public:
    int solve(int n, int k) {
        vector<vector<LL>> dp(n+1, vector<LL>(n+1));
        for(int i = 0; i <= n; ++ i) {
            for(int j = i; j <= n; ++ j) {
                if(i == 0 || j == 0) {
                    dp[i][j] = 1;
                }
                else if(i == j) {
                    for(int k = 0; k < i; ++ k) {
                        dp[i][i] += dp[k][k] * dp[i-k-1][i-k-1] % MOD;
                        dp[i][i] %= MOD;
                    }
                }
                else {
                    dp[i][j] = dp[i][j-1];
                    for(int k = 1; k <= i; ++ k) {
                        dp[i][j] += dp[i-k][j-k-1] * dp[k][k] % MOD;
                        dp[i][j] %= MOD;
                    }
                }
            }
        }
        if(k == 0) {
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