bool const cmp(const vector<int>& A, const vector<int>& B){
if(A[0]==B[0]) return A[1]<B[1];
return A[0]<B[0];
}
class Solution {
public:
int maxEnvelopes(vector<vector<int>>& envelopes) {
sort(envelopes.begin(),envelopes.end(),cmp);
int n = envelopes.size();
if(n < 2)return n;
for(int i = 0; i < n; i++){
cout<<"["<<envelopes[i][0]<<","<<envelopes[i][1]<<"]"<<endl;
}
vector<int> dp(n, 1);
int ans = 1;
for(int i = 1; i < n; i++){
for(int j = 0; j < i; j++){
if(envelopes[i][0]>envelopes[j][0] && envelopes[i][1]>envelopes[j][1]){
dp[i] = max(dp[j] + 1, dp[i]);
}
}
ans = max(ans, dp[i]);
}
return ans;
}
};