#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
const int MAXN = 5e2 + 5;
const int mod = 1e9 + 7;

inline void add_mod(int &a,int b){ a+=b; if(a>=mod) a-=mod;}

int n,d;
char s[MAXN];
int f[MAXN][MAXN], dp[MAXN][MAXN], dp2[MAXN][MAXN];

inline bool chk(int x){ return s[x] == '*' || s[x] == '?';}
inline bool chk(int l,int r)
{
	if(r-l+1 > d) return 0;
	for(int i=l; i<=r; ++i)
		if(!chk(i)) return 0;
	return 1;
}

int main(void)
{
//	freopen("bracket.in","r",stdin);
//	freopen("bracket.out","w",stdout);
	
	scanf("%d%d%s",&n,&d,s+1);
	
	for(int i=n; i>=1; --i)
		for(int j=i+1; j<=n; ++j)
		{
			if(s[i] != '*' && s[j] != '*' && s[i] != ')' && s[j] != '(')
			{
				if(chk(i+1, j-1)) f[i][j] = 1;// (), (S)
				
				add_mod(f[i][j], dp2[i+1][j-1]);// (A), (SA)
				for(int k=j-1; k>i && j-k<=d && chk(k); --k)
					add_mod(f[i][j], dp[i+1][k-1]);// (AS)
				
				dp[i][j] = f[i][j];
				for(int k=i; k<j; ++k)
					dp[i][j] = (dp[i][j] + (ll)f[i][k] * dp2[k+1][j]) %mod;// AB, ASB
			}
			
			dp2[i][j] = dp[i][j];
			for(int k=i; k<j && k-i+1<=d && chk(k); ++k)
				add_mod(dp2[i][j], dp[k+1][j]);
		}
	
	printf("%d",dp[1][n]);
	return 0;
}