func_code_string: #include <bits/stdc++.h>   int main() {     int n, k, i, start;     bool b;     while (scanf( %d%d , &n, &k) != EOF) {       if (n < k || k == 1 && n > 1) {         printf( -1 n );         continue;       }       start = k;       for (i = b = 0; i < n; i++) {         if (b && n - i == k - 2) {           start = 2;           break;         }         if (!b && n - i == k - 1) {           start = 1;           break;         }         printf(i& 1 ? b = 1,  b  :  a );       }       for (i = start; i < k; i++) printf( %c , i +  a );       printf(  n );     }     return 0;   }   