#include <bits/stdc++.h>
using namespace std;
#define int long long

const int mod = 998244353;

vector<int>fact(2000010);
vector<int>inv(2000010);
int modpow(int x, int y) {
    return !y?1:((y % 2 ? x : 1) * modpow((x * x) % mod, y / 2)) % mod;
}
int choose(int x, int y){
    if(y>x)return 0;
    return (fact[x]*inv[y]%mod)*inv[x-y]%mod;
}
int permute(int x, int y){
    if(y>x)return 0;
    return (fact[x]*inv[x-y])%mod;
}
void precalc(){
    fact[0] = 1; inv[0] = 1;
    for(int i = 1; i<=2000000; i++){
        fact[i] = fact[i-1]*i%mod;
    }
    inv[2000000] = modpow(fact[2000000],mod-2);
    for(int i = 1999999; i>0; i--){
        inv[i] = inv[i+1]*(i+1)%mod;
    }
}
signed main() {
    cin.tie(0)->sync_with_stdio(0); precalc();
    int t;
    cin >> t;
    while(t--){
        int n,k,m;
        cin >> n >> k >> m;
        string s,t;
        cin >> s >> t;
        int d = 0;
        for(int i = 0; i<n; i++){
            if(s[i]!=t[i]){
                d++;
            }
        }
        vector<vector<int>>dp(k+1,vector<int>(n+1));
        dp[0][0] = 1;
        for(int a = 1; a<=k; a++){
            for(int i = 0; i<=n; i++){
                for(int j = 0; j<=min(i,m); j++){
                    int p = i-j + (m-j);
                    dp[a][i]+=dp[a-1][p] * choose(i,j)%mod * choose(n-i,m-j)%mod;
                    dp[a][i]%=mod;
                }
            }
        }
        cout << dp[k][d] << '\n';


    }
    return 0;
}