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<cstdio>
const int MaxN=19,MaxM=20,mod=1000000007;
int N,M,K,req[MaxM][MaxN];
int f[1<<MaxN];
int add(int a,int b){return a+b>=mod?a+b-mod:a+b;}
int main(){
	scanf("%d%d%d",&N,&M,&K);--N;
	while(K--){
		int A,B,C;scanf("%d%d%d",&A,&B,&C);
		req[A-1][B-1]=1<<C;
	}
	f[0]=1;
	for(int i=0;i<M;i++)
	for(int j=0;j<N;j++)
	for(int r=req[i][j],s=1<<N;(s-=1<<N-j)>=0;){
		int ss=s|1<<N-j-1;
		if(r==1)
			for(int k=1<<N-j-1,t=k<<1;t-->k;)f[s|t]=0;
		else{
			for(int k=1<<N-j-1;k>>=1;){
				if(r)for(int sk=s|k,t=k;t--;)f[ss|t]=add(f[ss|t],f[sk|t]),f[sk|t]=0;
				else for(int sk=s|k,t=k;t--;)f[ss|t]=add(f[ss|t],f[sk|t]);
			}
			f[ss]=add(f[ss],f[s]);r?f[s]=0:1;
		}
	}
	int sum=0;
	for(int i=0;i<1<<N;i++)(sum+=f[i])%=mod;
	printf("%d\n",sum);
}