code_multchoice

/// solution : https://pastebin.com/1UWbv6PT
#include<bits/stdc++.h>
#define int             long long
using namespace std;

const int N = 2004, MOD = 1e9 + 7;
int n, P, Q, numAnswer[N];
char a[N], b[N];

int Equal[N], Diff[N], numEqual, numDiff;
int C[N][N];

void prepare() {
    for (int i = 0; i <= n; ++i) for (int j = 0; j <= i; ++j)
        C[i][j] = (j == 0 || j == i) ? 1 : (C[i-1][j] + C[i-1][j-1]) % MOD;

    for (int i = 1; i <= n; ++i) {
        if (a[i] == b[i]) Equal[++numEqual] = i;
        else Diff[++numDiff] = i;
    }
}

int dp[2][N][N];

int Mul(int a, int b, int c) { return ( (a * b) % MOD * c ) % MOD; }

void sol() {
    prepare();

    dp[0][0][0] = 1;
    for (int i = 1; i <= numEqual; ++i) for (int j = 0; j <= i; ++j)
        dp[0][i][j] = ( dp[0][i-1][j] + (j > 0) * dp[0][i-1][j-1] * (numAnswer[Equal[i]]-1) ) % MOD;

    dp[1][0][0] = 1;
    for (int i = 1; i <= numDiff; ++i) for (int j = 0; j <= i; ++j)
        dp[1][i][j] = ( dp[1][i-1][j] + (j > 0) * dp[1][i-1][j-1] * (numAnswer[Diff[i]]-2) ) % MOD;

    int res = 0;
    for (int i = 0; i <= numEqual; ++i) {
        int j = numEqual - i;
        int remain1 = P - j, remain2 = Q - j, sum = remain1 + remain2;
        if (remain1 < 0 || remain2 < 0) continue;

        if (numDiff < remain1 + remain2) continue;
        res += Mul( dp[0][numEqual][i], dp[1][numDiff][numDiff-sum], C[sum][remain1] );
        res %= MOD;
    }
    cout << res << '\n';
}

#undef int
int main() {
#define int             long long
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen("input.txt", "r")) {
        freopen("input.txt", "r", stdin);
    }
    else if (fopen("multchoice.inp", "r")) {
        freopen("multchoice.inp", "r", stdin);
        freopen("multchoice.out", "w", stdout);
    }

    cin >> n >> P >> Q;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    for (int i = 1; i <= n; ++i) cin >> b[i];
    for (int i = 1; i <= n; ++i) {
        char c;
        for (int j = 1; j <= 5; ++j) {
            cin >> c;
            if (c != '.') numAnswer[i]++;
        }
    }

    sol();

    return 0;
}