input: 
  def power_conversion() -> str:
      """ Convert the provided Python program to a C# program.
      >>> power_conversion()
      "public int Power(int x, int y){ if (y == 0){ return 1; } else{ return x * Power(x, y - 1); }}"
      """
  
output:     return "public int Power(int x, int y){ if (y == 0){ return 1; } else{ return x * Power(x, y - 1); }}"