def true_f_func(idx):
    num = 0
    num2 = 0
    result = 0
    array = [
        121,
        255,
        214,
        60,
        106,
        216,
        149,
        89,
        96,
        29,
        81,
        123,
        182,
        24,
        167,
        252,
        88,
        212,
        43,
        85,
        181,
        86,
        108,
        213,
        50,
        78,
        247,
        83,
        193,
        35,
        135,
        217,
        0,
        64,
        45,
        236,
        134,
        102,
        76,
        74,
        153,
        34,
        39,
        10,
        192,
        202,
        71,
        183,
        185,
        175,
        84,
        118,
        9,
        158,
        66,
        128,
        116,
        117,
        4,
        13,
        46,
        227,
        132,
        240,
        122,
        11,
        18,
        186,
        30,
        157,
        1,
        154,
        144,
        124,
        152,
        187,
        32,
        87,
        141,
        103,
        189,
        12,
        53,
        222,
        206,
        91,
        20,
        174,
        49,
        223,
        155,
        250,
        95,
        31,
        98,
        151,
        179,
        101,
        47,
        17,
        207,
        142,
        199,
        3,
        205,
        163,
        146,
        48,
        165,
        225,
        62,
        33,
        119,
        52,
        241,
        228,
        162,
        90,
        140,
        232,
        129,
        114,
        75,
        82,
        190,
        65,
        2,
        21,
        14,
        111,
        115,
        36,
        107,
        67,
        126,
        80,
        110,
        23,
        44,
        226,
        56,
        7,
        172,
        221,
        239,
        161,
        61,
        93,
        94,
        99,
        171,
        97,
        38,
        40,
        28,
        166,
        209,
        229,
        136,
        130,
        164,
        194,
        243,
        220,
        25,
        169,
        105,
        238,
        245,
        215,
        195,
        203,
        170,
        16,
        109,
        176,
        27,
        184,
        148,
        131,
        210,
        231,
        125,
        177,
        26,
        246,
        127,
        198,
        254,
        6,
        69,
        237,
        197,
        54,
        59,
        137,
        79,
        178,
        139,
        235,
        249,
        230,
        233,
        204,
        196,
        113,
        120,
        173,
        224,
        55,
        92,
        211,
        112,
        219,
        208,
        77,
        191,
        242,
        133,
        244,
        168,
        188,
        138,
        251,
        70,
        150,
        145,
        248,
        180,
        218,
        42,
        15,
        159,
        104,
        22,
        37,
        72,
        63,
        234,
        147,
        200,
        253,
        100,
        19,
        73,
        5,
        57,
        201,
        51,
        156,
        41,
        143,
        68,
        8,
        160,
        58,
    ]
    for i in range(idx + 1):
        num += 1
        num %= 256
        num2 += array[num]
        num2 %= 256
        num3 = array[num]
        array[num] = array[num2]
        array[num2] = num3
        result = array[(array[num] + array[num2]) % 256]
    return result