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).

<image>

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 <bits/stdc++.h>

using namespace std;

using ll = long long;
using vi = vector<int>;
using db = double;
#define pb push_back

const ll mod = 1000000007;

int n, m, q;
ll f[1 << 19];
int msk[21];
int asn[21];
int u;

bool leg(int x, int s) {
	return (s & msk[x]) == asn[x];
}

int lowbit(int x) { return x & -x; }

int main() {
	cin >> n >> m >> q;
	if (n == 1) {
		cout << 1 % mod << endl;
		return 0;
	}
	
	--n;
	u = 1 << n;
	
	for (int i = 0; i < q; ++i) {
		int a, b, c;
		cin >> a >> b >> c;
		msk[a] |= 1 << b - 1;
		asn[a] |= c << b - 1;
	}
	
	
	f[0] = 1;
	for (int i = 1; i <= m; ++i) {
		for (int k = 0; k < n; ++k)
			for (int j = 0; j < u; ++j) if (~j >> k & 1)
				(f[j + (1 << k) - lowbit(j & ~((1 << k) - 1))] += f[j]) %= mod;
		for (int j = 0; j < u; ++j) if (!leg(i, j))
			f[j] = 0;
	}
	
	ll ans = 0;
	for (int i = 0; i < u; ++i)
		ans += f[i];
	
	cout << ans % mod << endl;
	
	return 0;
}