func_code_string: #include <bits/stdc++.h>   using namespace std;   bool prime[101];   void SieveOfEratosthenes(int n) {     memset(prime, true, sizeof(prime));     for (int p = 2; p * p <= n; p++) {       if (prime[p] == true) {         for (int i = p * p; i <= n; i += p) prime[i] = false;       }     }   }   int main() {     long long n, m;     cin >> n;     long long c[n + 1];     if (n % 2 != 0) {       cout << -1;       return 0;     }     for (long long i = 1; i <= n; i++) {       c[i] = i;     }     for (long long i = 1; i <= n; i += 2) {       swap(c[i], c[i + 1]);     }     for (long long i = 1; i <= n; i++) {       cout << c[i] <<    ;     }   }   