using System;
using System.Linq;
using System.Collections.Generic;

public class Test
{
	class Data {
		public int index;
		public string[] types;
	}
	
	public static void Main()
	{
		List<Data> dataList = new List<Data>();
		
		dataList.Add(new Data(){index = 1, types = new string[]{"street_number", "tits_size"}});
		dataList.Add(new Data(){index = 2, types = new string[]{"route", "ass_size"}});
		dataList.Add(new Data(){index = 3, types = new string[]{"street_number"}});
		dataList.Add(new Data(){index = 4, types = new string[]{"locality"}});
		
		var neededData = dataList.FindLast(data => data.types.Contains("street_number"));
		
		Console.WriteLine(neededData.index);
	}
}