input: 
  from typing import List
  
  def convert_to_csharp(python_code: List[str]) -> List[str]:
      """ Converts a given Python program to a C# program.
      >>> convert_to_csharp([
      ...     'def power(x, y):',
      ...     '    if y == 0:',
      ...     '        return 1',
      ...     '    else:',
      ...     '        return x * power(x, y - 1)'
      ... ])
      [
          'public int Power(int x, int y)',
          '{',
          '    if (y == 0)',
          '    {',
          '        return 1;',
          '    }',
          '    else',
          '    {',
          '        return x * Power(x, y - 1);',
          '    }',
          '}'
      ]
      """
  
output:     csharp_code = []
      for line in python_code:
          line = line.strip()
          if line.startswith("def "):
              line = line.replace("def ", "public ").replace(":", "")
              line += ")"
              csharp_code.append(line)
              csharp_code.append("{")
          elif line.startswith("if "):
              line = line.replace("if ", "if (").replace(":", ")")
              csharp_code.append("    " + line)
              csharp_code.append("    {")
          elif line.startswith("else:"):
              line = line.replace("else:", "else")
              csharp_code.append("    " + line)
              csharp_code.append("    {")
          elif line.startswith("return "):
              line = line.replace("return ", "return ") + ";"
              csharp_code.append("    " + line)
          elif line.startswith("    "):
              line = line.replace("    ", "    ")
              csharp_code.append(line)
      csharp_code.append("}")
      return csharp_code