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int numOfWays(int n) {
    long long mod = 1e9 + 7;
    long long aba = 6;
    long long abc = 6;

    for (int i = 1; i < n; i++) {
        long long next_aba = (aba * 3 + abc * 2) % mod;
        long long next_abc = (aba * 2 + abc * 2) % mod;
        aba = next_aba;
        abc = next_abc;
    }

    return (int)((aba + abc) % mod);
}