#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int largestPerimeter(vector<int>& A) {
sort(A.begin(),A.end());//排序結果是從小到大
for(int i=A.size()-3;i>=0;i--){
if(A[i]+A[i+1]>A[i+2]&&A[i+2]-A[i+1]<A[i])
return A[i]+A[i+1]+A[i+2];
}
return 0;
}
int main(){
vector<int> A={3,2,3,4};
cout<<largestPerimeter(A);
return 0;
}