#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N = 2e5+,MOD =  ;

ll n,m;

char s1[N],s2[N];

ll sum[N];

ll qp(ll a,ll b){

    ll ans = ;

    while(b){

        if(b&) ans=a*ans%MOD;

        a=a*a%MOD;

        b>>=;

    }

    return ans ;

}

int main(){

    scanf("%d%d",&n,&m);

    scanf("%s",s1);

    scanf("%s",s2);

    if(s1[n-]=='') sum[]=;

    for(int i=n-;i>=;i--){

        if(s1[i]=='') sum[n-i-]=(sum[n-i-]+qp(,n--i))%MOD;

        else sum[n-i-]=sum[n-i-];

    }

    ll ans = ;

    for(int i=m-;i>=;i--){

        if(s2[i]==''){

            ans=(ans+sum[min(m--i,n-)])%MOD;

        }

    }

    cout<<ans;

    return ;

}