#include <bits/stdc++.h>
using namespace std;
pair<long long,long long> dp[1001][1001][2][2];
string l,r;
string mo;
int org = 0;
pair<long long,long long> neg = {-1,-1};
long long mod = int(1e9)+7;
long long pw[1001];
//1000
//1001
//1010
//1101
//1110
//1111
//|R|L|R
//||R|L|R
//|R|R|L 1110
//||LR|L 1010
//||L|LL 1000
//|RL|R 1101
//|R|RR 1111
//L|L|R 1001
pair<long long,long long> solve(int i,int rem,int lowe,int uppe){
if(i==mo.size()){
return {(rem==0?1:0),0};
}
if(dp[i][rem][lowe][uppe]!=neg)return dp[i][rem][lowe][uppe];
int diff = (org-rem)%2;
char st = '0';
if(mo[i]=='R')st = '1';
pair<long long,long long>all = {0,0};
long long nu = 0;bool ss = 0;
for(char j = st;j<=st;j++){
char c = j;
if(diff){
if(c=='0')c = '1';
else c = '0';
}
if(c=='1')ss = 1;
if(c<r[i+1]){
if(c>l[i+1]){
all.first+=solve(i+1,rem,1,1).first;
all.second+=solve(i+1,rem,1,1).second;
all.first%=mod;
all.second%=mod;
if(ss)nu+=solve(i+1,rem,1,1).first;
nu%=mod;
}else if(c==l[i+1]||lowe){
all.first+=solve(i+1,rem,lowe,1).first;
all.second+=solve(i+1,rem,lowe,1).second;
all.first%=mod;
all.second%=mod;
if(ss)nu+=solve(i+1,rem,lowe,1).first;
nu%=mod;
}
}else if(c==r[i+1]||uppe){
if(c>l[i+1]){
all.first+=solve(i+1,rem,1,uppe).first;
all.second+=solve(i+1,rem,1,uppe).second;
all.first%=mod;
all.second%=mod;
if(ss)nu+=solve(i+1,rem,1,uppe).first;
nu%=mod;
}else if(c==l[i+1]||lowe){
all.first+=solve(i+1,rem,lowe,uppe).first;
all.second+=solve(i+1,rem,lowe,uppe).second;
all.first%=mod;
all.second%=mod;
if(ss)nu+=solve(i+1,rem,lowe,uppe).first;
nu%=mod;
}
}
}
int orginalRem = rem;
if(rem>0){
rem--;
ss =0;
diff = !diff;
for(char j = st;j<=st;j++){
char c = j;
if(diff){
if(c=='0')c = '1';
else c = '0';
}
if(c=='1')ss=1;
if(c<r[i+1]){
if(c>l[i+1]){
all.first+=solve(i+1,rem,1,1).first;
all.second+=solve(i+1,rem,1,1).second;
all.first%=mod;
all.second%=mod;
if(ss)nu+=solve(i+1,rem,1,1).first;
nu%=mod;
}else if(c==l[i+1]||lowe){
all.first+=solve(i+1,rem,lowe,1).first;
all.second+=solve(i+1,rem,lowe,1).second;
all.first%=mod;
all.second%=mod;
if(ss)nu+=solve(i+1,rem,lowe,1).first;
nu%=mod;
}
}else if(c==r[i+1]||uppe){
if(c>l[i+1]){
all.first+=solve(i+1,rem,1,uppe).first;
all.second+=solve(i+1,rem,1,uppe).second;
all.first%=mod;
all.second%=mod;
if(ss)nu+=solve(i+1,rem,1,uppe).first;
nu%=mod;
}else if(c==l[i+1]||lowe){
all.first+=solve(i+1,rem,lowe,uppe).first;
all.second+=solve(i+1,rem,lowe,uppe).second;
all.first%=mod;
all.second%=mod;
if(ss)nu+=solve(i+1,rem,lowe,uppe).first;
nu%=mod;
}
}
}
}
all.second+=(nu*pw[(mo.size()-1)-i])%mod;
all.second%=mod;
return dp[i][orginalRem][lowe][uppe] =all;
}
signed main(){
pw[0] = 1;
for(int i = 1;i<=1000;i++){
pw[i] = (pw[i-1]*2)%mod;
}
long long n,k;
cin>>n>>k;
org =k;
cin>>mo>>l>>r;
for(int i = 0;i<=n;i++){
for(int j = 0;j<=k;j++){
dp[i][j][0][0] = neg;
dp[i][j][1][0] = neg;
dp[i][j][1][1] = neg;
dp[i][j][0][1] = neg;
}
}
pair<long long,long long> sum = solve(0,k,0,0);
//
for(int i = 0;i<=n;i++){
for(int j = 0;j<=k;j++){
dp[i][j][0][0] = neg;
dp[i][j][1][0] = neg;
dp[i][j][1][1] = neg;
dp[i][j][0][1] = neg;
}
}
for(int i =0 ;i<mo.size();i++){
if(mo[i]=='R')mo[i] ='L';
else mo[i] = 'R';
}
sum.first+=solve(0,k,0,0).first;
sum.second+=solve(0,k,0,0).second;
cout<<((pw[n-1]*sum.first)%mod+sum.second)%mod<<endl;
}
