public static void Main()
Console.WriteLine("Enter the number of test cases required");
x=Int32.Parse(Console.ReadLine());
Console.WriteLine("Enter a string");
string str = Console.ReadLine();
Console.WriteLine("Enter the values to extract substring from");
int n = Int32.Parse(Console.ReadLine());
int m = Int32.Parse(Console.ReadLine());
string str1 = str.Substring(0,n);
string str2 = str.Substring(str1.Length,m);
char[] ch = new char[str2.Length];
string str3 = str.Substring(str1.Length+str2.Length);
string strans = str1+str2+str3;
Console.WriteLine("The output is {0}",strans);