#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <queue>
using namespace std;

int N, K;

string lwall, rwall;
bool Visited[2][200005];

bool check(bool wall, int height)
{
    if(wall == 0)
        return lwall[height] != 'X';

    else
    {
        return rwall[height] != 'X';
    }
    return false;
}


void bfs()
{
    queue < pair < bool , int > > Q; // SOL = 0 , SAG = 1
    Q.push( make_pair ( 0, 1 ) );
    Visited[0][1] = true;

    bool possible = false;
    bool wall;
    int height;
    while(!Q.empty())
    {
        wall = Q.front().first;
        height = Q.front().second;
        Q.pop();

        cout << wall << " " << height << endl;

        if(height >= N)
        {
            possible = true;
            break;
        }

        if(Visited[wall][height+1] == 0)
        {
            if(check(wall,height+1))
            {
                Q.push( make_pair (wall, height+1) );
                Visited[wall][height+1] = true;
            }
        }
        if(height-1 > 0 && Visited[wall][height-1] == 0)
        {
            if(check(wall,height-1))
            {
                Q.push( make_pair (wall, height-1) );
                Visited[wall][height-1] = true;
            }
        }

        if(Visited[1-wall][height+K] == 0)
        {
            if(check(1-wall,height+K))
            {
                Q.push( make_pair (1-wall, height+K) );
                Visited[1-wall][height+K] = true;
            }
        }
    }

    if(possible)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;

}

int main() {

    cin >> N >> K;
    cin >> lwall >> rwall;
    lwall = '.' + lwall;
    rwall = '.' + rwall;
    bfs();

    return 0;
}