public static void Main()
Console.WriteLine((Isshuffle("abc", "def", "dabecf")));
Console.WriteLine((Isshuffle("bac", "def", "dabecf")));
Console.WriteLine((Isshuffle("otto", "anna", "")));
Console.WriteLine((Isshuffle("otto", "anna", "oatntnoa")));
public static bool Isshuffle(string s1, string s2, string res){
char[] a1 = s1.ToCharArray();
char[] a2 = s2.ToCharArray();
if(p1<a1.Length && a == a1[p1]){
}else if(p2<a2.Length && a == a2[p2]){