#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 3007;
const ll inf = 2e9;
const ll mod = 1e9 + 7;
const double pi = acos(-1);
const double eps = 1e-6;
const int dx[] = {0, -1, 0, 1}, dy[] = {1, 0, -1, 0};
const int block = 320;
ll n, k, dp[M][M][2][2], dp2[M][M][2][2];
string s, a, b;
ll solve(string x){
for(int i = 0; i <= n; ++i) for(int j = 0; j <= k; ++j) for(int Smaller : {0, 1}) for(int flip : {0, 1}) dp[i][j][Smaller][flip] = dp2[i][j][Smaller][flip] = 0;
dp[0][0][x[0] == '0'][0] = dp[0][0][x[0] == '0'][1] = 1;
dp2[0][0][x[0] == '0'][0] = dp2[0][0][x[0] == '0'][1] = 1;
for(int i = 0; i < n - 1; ++i){
for(int j = 0; j <= k; ++j){
for(int flip : {0, 1}){
ll on = (s[i + 1] - '0') ^ flip;
bool isSmaller1 = (x[i + 1] == '1' && on == 0);
bool isSmaller2 = (x[i + 1] == '1' && on);
dp[i + 1][j][1][flip] = (dp[i + 1][j][1][flip] + dp[i][j][1][flip]) % mod;
dp[i + 1][j + 1][1][!flip] = (dp[i + 1][j + 1][1][!flip] + dp[i][j][1][flip]) % mod;
dp2[i + 1][j][1][flip] = (dp2[i + 1][j][1][flip] + 2 * dp2[i][j][1][flip] + dp[i][j][1][flip] * on) % mod;
dp2[i + 1][j + 1][1][!flip] = (dp2[i + 1][j + 1][1][!flip] + 2 * dp2[i][j][1][flip] + dp[i][j][1][flip] * !on) % mod;
if(x[i + 1] == '1' || !on) dp[i + 1][j][isSmaller1][flip] = (dp[i + 1][j][isSmaller1][flip] + dp[i][j][0][flip]) % mod;
if(x[i + 1] == '1' || on) dp[i + 1][j + 1][isSmaller2][!flip] = (dp[i + 1][j + 1][isSmaller2][!flip] + dp[i][j][0][flip]) % mod;
if(x[i + 1] == '1' || !on) dp2[i + 1][j][isSmaller1][flip] = (dp2[i + 1][j][isSmaller1][flip] + 2 * dp2[i][j][0][flip] + dp[i][j][0][flip] * on) % mod;
if(x[i + 1] == '1' || on) dp2[i + 1][j + 1][isSmaller2][!flip] = (dp2[i + 1][j + 1][isSmaller2][!flip] + 2 * dp2[i][j][0][flip] + dp[i][j][0][flip] * !on) % mod;
}
}
}
ll ret = 0;
for(int i : {0, 1})
for(int j : {0, 1})
ret = (ret + dp2[n - 1][k][i][j]) % mod;
return ret;
}
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> k >> s >> a >> b;
s = '#' + s;
for(int i = 1; i < n; ++i){
if(s[i] == 'L') s[i] = '0';
else s[i] = '1';
}
for(int i = n - 1; i >= 0; --i){
if(a[i] == '0') a[i] = '1';
else{
a[i] = '0';
break;
}
}
cout << (solve(b) - solve(a) + mod) % mod;
return 0;
}
