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

public static string Repeat(this string str, int n) {
    return new string('X', n).Replace("X", str + '\n');
}


List<string> list1 = new List<string>() {"foo", "baz", "bar", "yada"};
List<int> list2 = new List<int>() { 1,2,3,4,5 };

var result = list1.Zip(list2, (first, second) => first.Repeat(second));

foreach (var r in result) {
    Console.WriteLine(r);
}