func_code_string: #include <bits/stdc++.h>   using namespace std;   int A[1001][1001];   int n, m, k, i, j, l, r, a, b, x, y, p, q;   int main() {     cin >> n >> a >> b;     x = n / 2;     y = n - x;     p = 1;     q = 2;     for (i = 1; i <= a; i++)       for (j = 1; j <= b; j++) {         l = A[i - 1][j] % 2;         r = A[i][j - 1] % 2;         if (j == 1) r = l;         if (i == 1) l = r;         if (l != r) continue;         if (l == 1 && x)           A[i][j] = q, q += 2, x--;         else if (l == 0 && y)           A[i][j] = p, p += 2, y--;       }     if (x != 0 || y != 0) {       cout << -1;       return 0;     }     for (i = 1; i <= a; i++) {       for (j = 1; j <= b; j++) cout << A[i][j] <<    ;       cout << endl;     }   }   