Problem: There are N squares arranged in a row. The squares are numbered 1, 2, ..., N, from left to right.

Snuke is painting each square in red, green or blue. According to his aesthetic sense, the following M conditions must all be satisfied. The i-th condition is:

* There are exactly x_i different colors among squares l_i, l_i + 1, ..., r_i.



In how many ways can the squares be painted to satisfy all the conditions? Find the count modulo 10^9+7.

Constraints

* 1 ≤ N ≤ 300
* 1 ≤ M ≤ 300
* 1 ≤ l_i ≤ r_i ≤ N
* 1 ≤ x_i ≤ 3

Input

Input is given from Standard Input in the following format:


N M
l_1 r_1 x_1
l_2 r_2 x_2
:
l_M r_M x_M


Output

Print the number of ways to paint the squares to satisfy all the conditions, modulo 10^9+7.

Examples

Input

3 1
1 3 3


Output

6


Input

4 2
1 3 1
2 4 2


Output

6


Input

1 3
1 1 1
1 1 2
1 1 3


Output

0


Input

8 10
2 6 2
5 5 1
3 5 2
4 7 3
4 4 1
2 3 1
7 7 1
1 5 2
1 7 3
3 4 2


Output

108

Solution (in PYTHON3):

Solution:
from itertools import permutations
n,m = map(int,input().split())
lrx = [list(map(int,input().split())) for i in range(m)]
lrx.sort(key = lambda x:x[1])
mod = 10**9+7
dp = [[[0 for b in range(max(1,g))] for g in range(max(1,r))] for r in range(n+1)]
dp[0][0][0] = 1
for l,r,t in lrx:
  if t != 1:
    for g in range(l):
      for b in range(max(1,g)):
        dp[r][g][b] = -1
  if t != 2:
    for g in range(l,r):
      for b in range(l):
        dp[r][g][b] = -1
  if t != 3:
    for g in range(l,r):
      for b in range(l,g):
        dp[r][g][b] = -1

for r in range(n):
  for g in range(max(1,r)):
    for b in range(max(1,g)):
      v = dp[r][g][b]
      if v == -1:
        continue
      if dp[r+1][g][b] >= 0:
        dp[r+1][g][b] += v
        dp[r+1][g][b] %= mod
      if dp[r+1][r][b] >= 0:
        dp[r+1][r][b] += v
        dp[r+1][r][b] %= mod
      if dp[r+1][r][g] >= 0:
        dp[r+1][r][g] += v
        dp[r+1][r][g] %= mod
ans = 0
for i in range(n):
  for j in range(max(1,i)):
    if dp[n][i][j] >= 0:
      ans += dp[n][i][j]
      ans %= mod
print(ans%mod)