#D1197. 2 - Non-triangular Triplets
2 - Non-triangular Triplets
2 - Non-triangular Triplets
Given are positive integers N and K.
Determine if the 3N integers K, K+1, ..., K+3N-1 can be partitioned into N triples (a_1,b_1,c_1), ..., (a_N,b_N,c_N) so that the condition below is satisfied. Any of the integers K, K+1, ..., K+3N-1 must appear in exactly one of those triples.
- For every integer i from 1 to N, a_i + b_i \leq c_i holds.
If the answer is yes, construct one such partition.
Constraints
- 1 \leq N \leq 10^5
- 1 \leq K \leq 10^9
Input
Input is given from Standard Input in the following format:
N K
Output
If it is impossible to partition the integers satisfying the condition, print -1
. If it is possible, print N triples in the following format:
a_1 b_1 c_1 : a_N b_N c_N
Output
If it is impossible to partition the integers satisfying the condition, print -1
. If it is possible, print N triples in the following format:
a_1 b_1 c_1 : a_N b_N c_N
Examples
Input
1 1
Output
1 2 3
Input
3 3
Output
-1
inputFormat
Input
Input is given from Standard Input in the following format:
N K
outputFormat
Output
If it is impossible to partition the integers satisfying the condition, print -1
. If it is possible, print N triples in the following format:
a_1 b_1 c_1 : a_N b_N c_N
Output
If it is impossible to partition the integers satisfying the condition, print -1
. If it is possible, print N triples in the following format:
a_1 b_1 c_1 : a_N b_N c_N
Examples
Input
1 1
Output
1 2 3
Input
3 3
Output
-1
样例
3 3
-1