哈哈哈~~~~~~~~

#include <iostream>
#include <vector>
using namespace std;

int main() {
	int n;
	cin >> n;
	vector<int> nums(n);
	for (int i = 0; i < n; ++i) {
    	cin >> nums[i];
	}

	vector<vector<int>> dp(n, vector<int>(n, 0));
	for (int i = 0; i < n; ++i) {
    	dp[i][i] = nums[i];
	}

	for (int l = 2; l <= n; ++l) { // 区间长度
    	for (int i = 0; i <= n - l; ++i) {
        	int j = i + l - 1;
        	dp[i][j] = max(nums[i] - dp[i+1][j], nums[j] - dp[i][j-1]);
    	}
	}

	cout << (dp[0][n-1] >= 0 ? "true" : "false") << endl;

	return 0;
}