#include <algorithm>
#include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <cstring>
#include <ctime>
#include <cassert>
using namespace std;
typedef long long LL;
#define FOR(k,a,b) for(int k(a); k < (b); ++k)
#define FORD(k,a,b) for(int k(b-1); k >= (a); --k)
#define REP(k,a) for(int k=0; k < (a); ++k)
#define ABS(a) ((a)>0?(a):-(a))

char X[22], Y[22], tmpc[22];

const LL MOD = 1e9+7;
const int ALPHABETNUM = 'Z'-'A' + 1;
int N,K,T;

int calcState(char* c)
{
	if(c[0]==0) return 0;
	int stX=0;//0 is equal X, 1 strictly less, 2 strictly greater
	int stY=0;//
	char Z = strlen(c);
	for(int i = 0; c[i]; ++i)
	{
		if(i == K) return 60;
		if(stX == 0)
		{
			if(c[i]>X[i])
				stX = 2;
			else if (c[i]<X[i])
				stX = 1;
		}
		if(stY == 0)
		{
			if(c[i]>Y[i])
				stY = 2;
			else if (c[i]<Y[i])
				stY = 1;
		}
		if(stX==1 || stY==2)
			return calcState(c+1);
		if(stX==2 && stY==1)
			return 40 + Z;
	}
	if(stX == 0)
		return Z;
	if(stY == 0)
		return 20+Z;
	assert(false);
}

int step(int state, char c)
{
	if(state == 60) // surely contain hated word
		return 60;
	if(state < 20) // yet is equal with X prefix len = state
	{
		int len = state ;
		if(len > strlen(X)) return 60;
		REP(i,len)
			tmpc[i]=X[i];
		tmpc[len]=c;
		tmpc[len+1] = 0;
		return calcState(tmpc);
	}
	if(state < 40) // yet is equal with Y prefix len (and strictly larger than X) = state -20
	{
		int len = state -20;
		if(len > strlen(Y)) return 60;
		REP(i,len)
			tmpc[i]=Y[i];
		tmpc[len]=c;
		tmpc[len+1] = 0;
		return calcState(tmpc);
	}
	// this contain a surely hated word prefix with state - 40 len
	int len = state -40;
	if(len<K-1)
		return state + 1;
	return 60;
}

int main( int argc, char* argv[] ) {
#ifdef HOME
	freopen("in.txt","r",stdin);
	freopen("out.txt","wb",stdout);
#endif
	scanf("%d",&T);
	while(T--)
	{
		scanf("%d",&N);
		scanf("%s",&X);
		scanf("%s",&Y);
		K=strlen(X);
		int Z=0;
		for(;Z<K;++Z)
		{
			if(X[Z]!=Y[Z])
				break;
		}
		int moves[61][ALPHABETNUM];
		memset(moves,0,sizeof moves);
		REP(i,61) REP(j,ALPHABETNUM)
		{
			moves[i][j]=step(i,'A'+j);
		}
		LL dp[20][61];
		memset(dp,0,sizeof dp);
		dp[0][0]=1;
		REP(i,N)
		{
			REP(j,61) REP(K,ALPHABETNUM)
			{
				dp[i+1][moves[j][K]]+=dp[i][j];
				dp[i+1][moves[j][K]]%=MOD;
			}
		}
		LL ans = 0;
		REP(i,K)
			ans= (ans + dp[N][i] + dp[N][20+i] + dp[N][40+i]) % MOD;
		printf("%lld",ans);
	}
	return 0;
}