func_code_string: #include <bits/stdc++.h>   using namespace std;   int n;   int b[200010];   map<int, long long> S;   long long solve() {     S.clear();     long long df, ans = 0;     for (int i = 0; i < n; i++) {       df = b[i] - i;       S[df] += (long long)b[i];     }     map<int, long long>::iterator it;     for (it = S.begin(); it != S.end(); it++) ans = max(ans, it->second);     return ans;   }   int main() {     cin >> n;     for (int i = 0; i < n; i++) cin >> b[i];     cout << solve() << endl;   }   