/*可能是因为string导致7~10爆了空间
*/
#include<iostream>
#include<cstdio>
#include<cstring>
#define maxn 500010
using namespace std;
int n,w,nxt[maxn],ans;
string s;
bool vis[maxn];
void getnxt(){int i=0,j=-1;nxt[0]=-1;while(i!=n){if(s[i]==s[j]||j==-1)nxt[++i]=++j;else j=nxt[j];}
}
void dfs(string c,int len){if(!vis[len]&&len<=w)vis[len]=1,ans++;else return;int j=nxt[n];while(j){dfs(c+s.substr(j,n-j),len+(n-j));j=nxt[j];}dfs(c+s,len+n);
}
int main(){int T;scanf("%d",&T);while(T--){memset(vis,0,sizeof(vis));ans=0;scanf("%d%d",&n,&w);cin>>s;getnxt();dfs(s,n);printf("%d\n",ans);}
}

#include<cstdio>
#include<cstring>
#include<algorithm>
#define LL long long
using namespace std;
inline int read()
{int t=1,sum=0;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-') t=-1;ch=getchar();}while(ch>='0'&&ch<='9')sum=sum*10+ch-'0',ch=getchar();return t*sum;
}
const int Max=1e6+10;
const LL inf=1e18;
int nxt[Max],q[Max],Q[Max],len[Max],n,nm;
LL f[Max],w[Max],W; char s[Max];
void get_nxt()
{int i,j;for(nxt[1]=j=0,i=2;i<=n;i++){while(j&&s[j+1]!=s[i]) j=nxt[j];nxt[i]=s[j+1]==s[i]?++j:j;}
}
int gcd(int a,int b)
{return !b?a:gcd(b,a%b);
}
void change(int x)
{int d=gcd(x,nm),i,j,tot; static LL pre[Max];for(i=0;i<nm;i++) pre[i]=f[i];for(i=0;i<x;i++) f[i]=inf;for(i=0;i<nm;i++) if(pre[i]!=inf)j=pre[i]%x,f[j]=min(f[j],pre[i]);for(i=0;i<d;i++){tot=0; j=i;while(true){q[++tot]=j;j=(j+nm)%x;if(j==i) break;}for(j=1;j<=tot;j++) q[tot+j]=q[j];tot<<=1;for(j=2;j<=tot;j++) f[q[j]]=min(f[q[j]],f[q[j-1]]+nm);}nm=x;
}
void update(int a0,int d,int num)
{int D=gcd(d,a0),i,j,k,tot,N,l,r; static LL w[Max],mi; change(a0);for(i=0;i<D;i++){tot=0; j=i;while(true){q[++tot]=j;j=(j+d)%a0;if(j==i) break;}for(mi=inf,j=1;j<=tot;j++) if(f[q[j]]<mi) mi=f[q[j]],k=j;if(mi==inf) continue;else N=0;for(j=k;j<=tot;j++) Q[++N]=q[j];for(j=1;j<k;j++) Q[++N]=q[j];q[1]=l=r=1; w[1]=f[Q[1]]-d;for(j=2;j<=N;j++){if(q[l]+num<=j) l++;if(l<=r) f[Q[j]]=min(f[Q[j]],w[l]+1LL*j*d+a0);while(l<=r&&w[r]>=f[Q[j]]-1LL*j*d) r--;q[++r]=j; w[r]=f[Q[j]]-1LL*j*d;}}
}
int main()
{int T=read(),i,j,k; LL ans;while(T--){n=read(); scanf("%lld",&W); W-=n;scanf("%s",s+1); get_nxt();if(W<0){puts("0");continue;}for(j=0,i=nxt[n];i;i=nxt[i]) len[++j]=n-i;for(i=1;i<=(j>>1);i++) swap(len[i],len[j-i+1]);for(f[0]=0,i=1;i<n;i++) f[i]=inf;nm=n;for(i=1;i<=j;i=k){if(i==j) {update(len[i],1,1);break;}for(k=i+1;k<=j&&len[i]-len[i+1]==len[k-1]-len[k];k++);update(len[k-1],len[i]-len[i+1],k-i);}for(ans=i=0;i<nm;i++)if(f[i]!=inf&&f[i]<=W)ans+=(W-f[i])/nm+1;printf("%lld\n",ans);}return 0;
}