Problem: There are N(N+1)/2 dots arranged to form an equilateral triangle whose sides consist of N dots, as shown below. The j-th dot from the left in the i-th row from the top is denoted by (i, j) (1 \leq i \leq N, 1 \leq j \leq i). Also, we will call (i+1, j) immediately lower-left to (i, j), and (i+1, j+1) immediately lower-right to (i, j).

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Takahashi is drawing M polygonal lines L_1, L_2, ..., L_M by connecting these dots. Each L_i starts at (1, 1), and visits the dot that is immediately lower-left or lower-right to the current dots N-1 times. More formally, there exist X_{i,1}, ..., X_{i,N} such that:

* L_i connects the N points (1, X_{i,1}), (2, X_{i,2}), ..., (N, X_{i,N}), in this order.
* For each j=1, 2, ..., N-1, either X_{i,j+1} = X_{i,j} or X_{i,j+1} = X_{i,j}+1 holds.



Takahashi would like to draw these lines so that no part of L_{i+1} is to the left of L_{i}. That is, for each j=1, 2, ..., N, X_{1,j} \leq X_{2,j} \leq ... \leq X_{M,j} must hold.

Additionally, there are K conditions on the shape of the lines that must be followed. The i-th condition is denoted by (A_i, B_i, C_i), which means:

* If C_i=0, L_{A_i} must visit the immediately lower-left dot for the B_i-th move.
* If C_i=1, L_{A_i} must visit the immediately lower-right dot for the B_i-th move.



That is, X_{A_i, {B_i}+1} = X_{A_i, B_i} + C_i must hold.

In how many ways can Takahashi draw M polygonal lines? Find the count modulo 1000000007.

Constraints

* 1 \leq N \leq 20
* 1 \leq M \leq 20
* 0 \leq K \leq (N-1)M
* 1 \leq A_i \leq M
* 1 \leq B_i \leq N-1
* C_i = 0 or 1
* No pair appears more than once as (A_i, B_i).

Input

Input is given from Standard Input in the following format:


N M K
A_1 B_1 C_1
A_2 B_2 C_2
:
A_K B_K C_K


Output

Print the number of ways for Takahashi to draw M polygonal lines, modulo 1000000007.

Examples

Input

3 2 1
1 2 0


Output

6


Input

3 2 2
1 1 1
2 1 0


Output

0


Input

5 4 2
1 3 1
4 2 0


Output

172


Input

20 20 0


Output

881396682

Solution (in CPP):

Solution:
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
#include <cmath>
using namespace std;

const int MaxN = 19;
const int MaxM = 20;
const int M = 1000000007;

int n, m, nK;
int rest[MaxM + 1][MaxN];

int f[1 << MaxN];

int main()
{
	cin >> n >> m >> nK, --n;

	for (int i = 1; i <= m; ++i)
		for (int j = 0; j < n; ++j)
			rest[i][j] = -1;

	for (int i = 0; i < nK; ++i)
	{
		int u, v, w;
		cin >> u >> v >> w, --v;

		rest[u][v] = w;
	}

	f[0] = 1;
	for (int i = 1; i <= m; ++i)
		for (int j = 0; j < n; ++j)
			for (int s = 0; s < 1 << n; ++s)
			{
				if (f[s] == 0)
					continue;

				int cur = f[s];

				if (rest[i][j] == 1 || s >> j & 1)
					f[s] = 0;

				if (rest[i][j])
				{
					int p = s >> j;
					int t = s ^ (((p & -p) ^ 1) << j);
					f[t] = (f[t] + cur) % M;
				}
			}

	int res = 0;
	for (int s = 0; s < 1 << n; ++s)
		res = (res + f[s]) % M;

	cout << res << endl;

	return 0;
}