#include <bits/stdc++.h>
using namespace std;
typedef long long int ll ;
int findDigitSum(int n){
int sum = 0;
int rem = 0;
while(n>0){
rem = n % 10;
n = n / 10;
sum += rem;
}
return sum;
}
int main() {
// Taking input
int n ;
cin >> n ;
ll arr[n] = {0};
ll i = 0 ;
while(i<=n){
cin >> arr[i]; i++;
}
// Solution
unordered_map<int,int> mpp;
int maxi = -1;
for(int n: arr){
int curDigitSum = findDigitSum(n);
if(mpp.find(curDigitSum) != mpp.end()){
int sum = n + mpp[curDigitSum];
maxi = max(maxi, sum);
}
mpp[curDigitSum] = max(n, mpp[curDigitSum]);
}
cout << maxi;
return 0;
}
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