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<bits/stdc++.h>
#define clr(a,x) memset(a,x,sizeof(a))
using namespace std;

const int N=(1<<19)+5,mod=1e9+7;

int n,m,k,d,bits[N],f[2][N]={1},a[22][20];
inline int calc(int x){return bits[x&-x];}
inline int ch(int &x,int y){x=(x+y)%mod;}

int main(){
	cin>>n>>m>>k;
	n--;clr(a,-1);
	for(int i=0;i<=n;i++)
		bits[1<<i]=i;
	for(int i=1;i<=k;i++){
		int a,b,c;
		cin>>a>>b>>c;
		b--;::a[a][b]=c;
	}for(int i=1;i<=m;i++)
		for(int j=0;j<n;j++,d^=1){
			clr(f[d^1],0);
			for(int k=0;k<(1<<n);k++){
				if(!f[d][k]) continue; 
				if(a[i][j]!=0) 	
					if(k>>j) ch(f[d^1][k^(1<<j)^(1<<calc(k>>j)+j)],f[d][k]); else ch(f[d^1][k^(1<<j)],f[d][k]);
				if(a[i][j]!=1&&!(k&(1<<j)))	ch(f[d^1][k],f[d][k]);
			}
		}
	int ans=0;
	for(int i=0;i<(1<<n);i++) ch(ans,f[d][i]);
	cout<<ans<<endl;
	return 0;
}