#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define IOS ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define CHECK cout<<"WALKED"<<endl;
inline int read(){int x=0,f=1;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();} while(ch>='0' && ch<='9')x=(x<<3)+(x<<1)+ch-'0',ch=getchar();return x*f;}
ll binpow(ll a, ll b, ll mod){ll res = 1;  while (b > 0){if (b & 1) res = res * a % mod;a = a * a % mod;  b >>= 1;  }  return res;}
using namespace std;

const int N = 505, p = 1e9 + 7;
ll f[6][N][N];
char str[N];
int n, lim;
ll S[N][N], SA[N][N], AS[N][N]; // bool cao!!!

bool lbl(char c) { return c == '(' || c == '?';}
bool lbr(char c) { return c == ')' || c == '?';}
bool jgs(char c) { return c == '*' || c == '?';}

void init()
{
	for (int i = 1; i <= n; i++) {
		if (!jgs(str[i])) continue;
		for (int j = i; j <= n && j < i + lim; j++) { // mamipulate k's restriction wisely
			if (!jgs(str[j])) break;
			S[i][j] = 1;
		}
	}
	
	for (int i = 1; i < n; i++)
		if (lbl(str[i]) && lbr(str[i + 1])) 
			f[0][i][i + 1] = f[1][i][i + 1] = f[2][i][i + 1] = 1;
}

int main()
{
	cin >> n >> lim;
	scanf("%s", str + 1);
	init();
	
	// % p;
	
	
	for (int len = 3; len <= n; len ++) { // from 3
		for (int l = 1; l <= n - len + 1; l ++) {
			int r = l + len - 1;
			
			f[2][l][r] = lbl(str[l]) * lbr(str[r]) *
						(S[l + 1][r - 1] + f[0][l + 1][r - 1] + SA[l + 1][r - 1] + AS[l + 1][r - 1]);
			f[2][l][r] %= p;
			f[0][l][r] = f[2][l][r];
			// use f qian 's meaning: avoid redundent counting
			for (int k = l + 1; k < r; k ++)
				f[0][l][r] = (f[0][l][r] + f[2][l][k] * f[0][k + 1][r]) % p;
			
			for (int k = l + 1; k < r; k++) 
				f[0][l][r] = (f[0][l][r] + f[2][l][k] * SA[k + 1][r]) % p;
			
			
			for (int k = max(r - lim + 1, l + 1); k <= r; k++) 
				AS[l][r] = (AS[l][r] + f[0][l][k - 1] * S[k][r]) % p;
			for (int k = l; k <= min(l + lim - 1, r - 1); k++)
				SA[l][r] = (SA[l][r] + S[l][k] * f[0][k + 1][r]) % p;
		}
	}
	f[0][1][n] %= p;
	printf("%d\n", f[0][1][n]);
	return 0;
}