using System;

public class Program

{

    public static void Main()

    {

        var v = "at=agent_mobile&mdf=3321c022832ee627c3b83a402f6cb90b&fc=45d5c191d720e5e9cb932c90ec39e7594a9d7b255cc0e79c&dr=http%3a%2f%2fcom.myyearbook.m&aov=7.1.2&am=nexus%206p&gr=8&fg=cb932c90ec39e7594a9d7b255cc0e79c&aca0=8c635bb5-4334-4336-8749-23a0b9ac0de9&nu=9827&alo=en_us&ah=eb09d33dd1934ec10d567defeff2688f&aos=android&al=en-us&lh=http%3a%2f%2fcom.myyearbook.m%2fmobile&z=60&w=45d5c191d720e5e9&av=3.0-105&c=60&ftsn=139&fts=64c72cb5327a40082480505879c00a09&f=1440x2392&la=45d5c191d720e5e9f2c66fab158c4f519124eb86a5630f52&grr=afile%3a%2f%2f%2fsu%3bafile%3a%2f%2f%2fsu%2fsu.d%3bafile%3a%2f%2f%2fsu%2fxbin%3bapkg%3a%2f%2feu.chainfire.supersu%3bfile%3a%2f%2f%2fsu%3bfile%3a%2f%2f%2fsu%2fsu.d%3bfile%3a%2f%2f%2fsu%2fxbin%3bpkg%3a%2f%2feu.chainfire.supersu%3b&ab=google%2c%20huawei&ls=f2c66fab158c4f519124eb86a5630f52&mds=892882d2f35d4247dbfebd59ab8e1df5&hh=9080ace4b39a8ce6ebd68d2c96663d58";

        var k = "kxm20z03ry4d3kcsgw3mgqwugngciwn6";

        var z = MeetmeXor(v, k);

        Console.WriteLine(z);

    }

    public static String MeetmeXor(String value, String key)

    {

        int v5;

        int v2;

        String v7 = value.Length + "&";

        byte[] v0 = new byte[value.Length + v7.Length];

        int v6 = key.Length;

        int v4 = 0;

        int v1 = 0;

        int v3 = 0;

        while (v3 < v7.Length)

        {

            v2 = v1 + 1;

            v5 = v4 + 1;

            v0[v1] = ((byte)((((byte)v7[v3])) ^ (((byte)key[v4])) & 10));

            v4 = v5 >= v6 ? 0 : v5;

            ++v3;

            v1 = v2;

        }

        v3 = 0;

        while (v3 < value.Length)

        {

            v2 = v1 + 1;

            v5 = v4 + 1;

            v0[v1] = ((byte)((((byte)value[v3])) ^ (((byte)key[v4])) & 10));

            v4 = v5 >= v6 ? 0 : v5;

            ++v3;

            v1 = v2;

        }

        return MeetmeBytesToHex(v0);

    }

    public static char[] HexArray = "0123456789abcdef".ToCharArray();

    private static String MeetmeBytesToHex(byte[] bytes)

    {

        char[] v0 = new char[bytes.Length * 2];

        int v1;

        for (v1 = 0; v1 < bytes.Length; ++v1)

        {

            int v2 = bytes[v1] & 255;

            v0[v1 * 2] = HexArray[(int)((uint)v2 >> 4)];

            v0[v1 * 2 + 1] = HexArray[v2 & 15];

        }

        return new String(v0);

    }

}

​