#D6834. Square
Square
Square
Takahashi has an N \times N grid. The square at the i-th row and the j-th column of the grid is denoted by (i,j). Particularly, the top-left square of the grid is (1,1), and the bottom-right square is (N,N).
An integer, 0 or 1, is written on M of the squares in the Takahashi's grid. Three integers a_i,b_i and c_i describe the i-th of those squares with integers written on them: the integer c_i is written on the square (a_i,b_i).
Takahashi decides to write an integer, 0 or 1, on each of the remaining squares so that the condition below is satisfied. Find the number of such ways to write integers, modulo 998244353.
- For all 1\leq i < j\leq N, there are even number of 1s in the square region whose top-left square is (i,i) and whose bottom-right square is (j,j).
Constraints
- 2 \leq N \leq 10^5
- 0 \leq M \leq min(5 \times 10^4,N^2)
- 1 \leq a_i,b_i \leq N(1\leq i\leq M)
- 0 \leq c_i \leq 1(1\leq i\leq M)
- If i \neq j, then (a_i,b_i) \neq (a_j,b_j).
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
N M a_1 b_1 c_1 : a_M b_M c_M
Output
Print the number of possible ways to write integers, modulo 998244353.
Examples
Input
3 3 1 1 1 3 1 0 2 3 1
Output
8
Input
4 5 1 3 1 2 4 0 2 3 1 4 2 1 4 4 1
Output
32
Input
3 5 1 3 1 3 3 0 3 1 0 2 3 1 3 2 1
Output
0
Input
4 8 1 1 1 1 2 0 3 2 1 1 4 0 2 1 1 1 3 0 3 4 1 4 4 1
Output
4
Input
100000 0
Output
342016343
inputFormat
input are integers.
Input
Input is given from Standard Input in the following format:
N M a_1 b_1 c_1 : a_M b_M c_M
outputFormat
Output
Print the number of possible ways to write integers, modulo 998244353.
Examples
Input
3 3 1 1 1 3 1 0 2 3 1
Output
8
Input
4 5 1 3 1 2 4 0 2 3 1 4 2 1 4 4 1
Output
32
Input
3 5 1 3 1 3 3 0 3 1 0 2 3 1 3 2 1
Output
0
Input
4 8 1 1 1 1 2 0 3 2 1 1 4 0 2 1 1 1 3 0 3 4 1 4 4 1
Output
4
Input
100000 0
Output
342016343
样例
100000 0
342016343