#include<bits/stdc++.h>
using namespace std;
#define rd(i,n) for(int i=0;i<n;i++)
#define rp(i,n) for(int i=1;i<=n;i++)
#define rep(i,a,b) for(int i=a;i<=b;i++)
#define per(i,a,b) for(int i=b;i>=a;i--)
#define pb push_back
#define vt vector
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll>pll;
const int N=5000005;
const int P=1000000007;
int n,m,a[N],f[31][11],g[31][11];
int tf[11],tg[11],C[31][31];
string s;
inline void upd(int &x,int y){
	x+=y;
	if(x>=P)x-=P;
}
inline int dfs(int x,int d){
	if(x>n)return 0;
	rep(i,0,m)f[d][i]=g[d][i]=0;
	f[d][1]=(s[x-1]=='0'),g[d][0]=1;
	//f是选了，g是没选
	int lsz=dfs(x<<1,d+1),sz=(s[x-1]=='0');
	if(lsz){
		rep(a,0,min(m,sz+lsz))tf[a]=tg[a]=0;
		rep(a,0,min(m,sz))rep(b,0,min(m-a,lsz)){
			upd(tf[a+b],1ll*f[d][a]*g[d+1][b]%P);
			upd(tg[a+b],1ll*g[d][a]*f[d+1][b]%P);
		}
		rep(a,0,min(m,sz+lsz)){
			f[d][a]=tf[a],tf[a]=0;
			g[d][a]=tg[a],tg[a]=0;
		}
		sz+=lsz;
	}
	// cout<<x<<"= ";
	// rep(a,0,m)cout<<f[d][a]<<' ';
	// cout<<endl;
	int rsz=dfs(x<<1|1,d+1);
	if(rsz){
		rep(a,0,min(m,sz+rsz))tf[a]=tg[a]=0;
		rep(a,0,min(m,sz))rep(b,0,min(m-a,rsz)){
			upd(tf[a+b],1ll*f[d][a]*g[d+1][b]%P);
			upd(tg[a+b],1ll*g[d][a]*f[d+1][b]%P);
		}
		rep(a,0,min(m,sz+rsz)){
			f[d][a]=tf[a],tf[a]=0;
			g[d][a]=tg[a],tg[a]=0;
		}
		sz+=rsz;
	}
	rep(a,0,min(m,sz)){
		upd(f[d][a],g[d][a]);
	}
	// cout<<x<<": ";
	// rep(a,0,m)cout<<f[d][a]<<' ';
	// cout<<endl;
	return sz;
}

signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	cin>>n>>m;
	cin>>s;
	dfs(1,0);
	rep(i,0,2*m){
		C[i][0]=1;
		rep(j,1,i)C[i][j]=(C[i-1][j]+C[i-1][j-1])%P;
	}
	int ans=0;
	rep(i,1,m){
		ans=(ans+1ll*f[0][i]%P*C[m-1][i-1]%P)%P;
	}
	cout<<ans<<endl;
	return 0;
}
//Rain Rain Rain