func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long INF = 2e18;   signed main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     long long n;     cin >> n;     vector<long long> a(n);     map<long long, long long> dp;     for (long long i = 0; i < n; ++i) {       cin >> a[i];       dp[a[i]] = dp[a[i] - 1] + 1;     }     long long x, mx = -INF;     for (auto &[last, len] : dp) {       if (len > mx) {         mx = len;         x = last;       }     }     cout << mx <<   n ;     long long l = x - mx + 1;     for (long long i = 0; i < n; ++i) {       if (a[i] == l) {         cout << i + 1 <<    ;         ++l;       }     }   }   