#include<iostream>
#include<cstring>
#define MOD 998244353
#define LL long long
using namespace std;
char str1[3005],str2[3005];
LL Cmn[3005][3005];
LL dp[3005][3005];
int qpow(int base,int n){int ans=1;while(n){if(n%2){ans=1LL*ans*base%MOD;}base=1LL*base*base%MOD;n>>=1;}return ans;
}
//void makerev(){
//    for(int i=1;i<=3000;i++){
//        rev[i]=qpow(i,MOD-2);
//    }
//    return ;
//}
void MakeCmn(){memset(Cmn,0,sizeof Cmn);Cmn[0][0]=1; for(int n=1;n<=3000;n++){Cmn[n][0]=1;for(int m=1;m<=n;m++){Cmn[n][m]=Cmn[n-1][m-1]+Cmn[n-1][m];Cmn[n][m]%=MOD;}}
//    for(int i=1;i<=3000;i++){
//        for(int j=1;j<=i;j++){
//            printf("从%d里取%d个的方案是%d\n",i,j,Cmn[i][j]);
//        }
//    }
}
int l1,l2;
int main(){
//    makerev();
    MakeCmn();int t;scanf("%d",&t);while(t--){scanf("%d %d",&l1,&l2);scanf("%s %s",str1,str2);if(l1<l2){printf("0\n");continue;}else if(l1==l2){for(int i=0;i<l1;i++){if(str1[i]>str2[i])goto B;if(str1[i]<str2[i]){printf("0\n");goto A;}}printf("0\n");continue;B:;printf("1\n");A:;continue;}//第一个串比第二个长的情况LL ans=0;for(int i=l2+1;i<=l1;i++){ans+=Cmn[l1][i];ans%=MOD;for(int j=0;j<l1;j++){if(str1[j]=='0'){ans-=Cmn[l1-1-j][i-1];ans+=MOD;ans%=MOD;}}}
//        printf(">:%d\n",ans);dp[0][0] = 1;for (int i = 1; i <= l1; i++) {dp[i][0] = 1;for (int j = 1; j <= min(l2, i); j++) {dp[i][j] = dp[i-1][j];if (str1[i-1] == str2[j-1]) {dp[i][j] = (0LL+dp[i][j] + dp[i-1][j-1]) % MOD;} else if (str1[i-1] > str2[j-1]) {ans = (0LL+ans + dp[i-1][j-1]*Cmn[l1-i][l2-j]) % MOD;}}}printf("%d\n",ans);}return 0;
}