func_code_string: #include <bits/stdc++.h>   using namespace std;   vector<int> s[100005];   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int n, m, i, j, a, b;     cin >> n >> m;     if (n == 1 && m == 1) {       cout <<  YES n  << 1;     } else if (n == 1 && m == 2) {       cout <<  NO ;     } else if (n == 2 && m == 1) {       cout <<  NO ;     } else if (n == 1 && m == 3) {       cout <<  NO ;     } else if (n == 3 && m == 1) {       cout <<  NO ;     } else if (n == 1 && m == 4) {       cout <<  YES n ;       cout <<  2 4 1 3 ;     } else if (n == 4 && m == 1) {       cout <<  YES n ;       cout <<  2 n4 n1 n3 ;     } else if (n == 2 && m == 2) {       cout <<  NO ;     } else if ((n == 2 && m == 3) || (n == 3 && m == 2)) {       cout <<  NO ;     } else if (n == 3 && m == 3) {       cout <<  YES n ;       cout <<  6 1 8 n7 5 3 n2 9 4 ;     } else if (n == 1 && m >= 5) {       vector<int> res;       for (i = 1; i <= m; i += 2) {         res.push_back(i);       }       for (i = 2; i <= m; i += 2) {         res.push_back(i);       }       cout <<  YES n ;       for (i = 0; i < m; i++) {         cout << res[i] <<    ;       }     } else if (n >= 5 && m == 1) {       vector<int> res;       for (i = 1; i <= n; i += 2) {         res.push_back(i);       }       for (i = 2; i <= n; i += 2) {         res.push_back(i);       }       cout <<  YES n ;       for (i = 0; i < n; i++) {         cout << res[i] <<   n ;       }     } else if (2 <= n && 4 <= m) {       a = 1;       for (i = 1; i <= n; i++) {         for (j = 1; j <= m; j++) {           s[i].push_back(a);           a++;         }       }       for (i = 2; i <= n; i += 2) {         a = s[i][0];         b = s[i][1];         for (j = 0; j < m - 2; j++) {           s[i][j] = s[i][j + 2];         }         s[i][m - 2] = a;         s[i][m - 1] = b;       }       for (i = 1; i < m; i += 2) {         a = s[1][i];         for (j = 1; j <= n - 1; j++) {           s[j][i] = s[j + 1][i];         }         s[n][i] = a;       }       cout <<  YES n ;       for (i = 1; i <= n; i++) {         for (j = 0; j < m; j++) {           cout << s[i][j] <<    ;         }         cout <<   n ;       }     } else {       a = 1;       for (i = 1; i <= n; i++) {         for (j = 1; j <= m; j++) {           s[i].push_back(a);           a++;         }       }       for (i = 1; i < m; i += 2) {         a = s[1][i];         b = s[2][i];         for (j = 1; j <= n - 2; j++) {           s[j][i] = s[j + 2][i];         }         s[n - 1][i] = a;         s[n][i] = b;       }       for (i = 2; i <= n; i += 2) {         a = s[i][0];         for (j = 0; j < m - 1; j++) {           s[i][j] = s[i][j + 1];         }         s[i][m - 1] = a;       }       cout <<  YES n ;       for (i = 1; i <= n; i++) {         for (j = 0; j < m; j++) {           cout << s[i][j] <<    ;         }         cout <<   n ;       }     }     return 0;   }   