using System;

using System.Collections;               

using System.Collections.Generic;           

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        var list = new List<Tuple<int,int>> { new Tuple<int,int>(5,2), new Tuple<int,int>(7,2), new Tuple<int,int>(3,9) };

        var index = Enumerable.Range(0, list.Count).Aggregate((p,c) => list[p].Item1 > list[c].Item1 ? c : p);

        var rotated = Enumerable.Range(0, list.Count).Select(i => list[(i + index) % list.Count]).ToList();

        Console.WriteLine(string.Join("; ", rotated.Select(r => r.Item1 + "," + r.Item2)));

    }

}

​