namespace AtCoder;

#nullable enable

using System.Numerics;

static class Extensions
{
    public static T[] Repeat<T>(this int time, Func<T> F) => Enumerable.Range(0, time).Select(_ => F()).ToArray();
}

class AtCoder
{
    object? Solve()
    {
        var n = Int();
        var p = Input<long>();
        var k = Int();
        var max = 1L;
        for (var i = 1; i <= 18; i++) max *= 10;
        max++;
        var min = long.MinValue / 4;
        var dp = new long[1];
        dp[0] = p;
        for (var i = 1; i <= n; i++)
        {
            var t = Int();
            var b = Int();
            var ep = new long[i + 1];
            for (var j = 0; j < i; j++) ep[j] = dp[j];
            ep[i] = min;
            for (var j = i - 1; j >= 0; j--) ep[j + 1] = Math.Max(ep[j + 1], t == 1 ? ep[j] + b : ep[j] * 2);
            for (var j = 0; j <= i; j++) ep[j] = Math.Min(ep[j], max);
            dp = ep;
        }
        var ans = dp[k];
        if (ans >= max) ans = -1;
        return ans;
    }

    public static void Main() => new AtCoder().Run();
    public void Run()
    {
        var res = Solve();
        if (res != null)
        {
            if (res is bool yes) res = yes ? "Yes" : "No";
            sw.WriteLine(res);
        }
        sw.Flush();
    }

    string[] input = Array.Empty<string>();
    int iter = 0;
    readonly StreamWriter sw = new(Console.OpenStandardOutput()) { AutoFlush = false };

    #pragma warning disable IDE0051
    string String()
    {
        while (iter >= input.Length) (input, iter) = (Console.ReadLine()!.Split(' '), 0);
        return input[iter++];
    }
    T Input<T>() where T : IParsable<T> => T.Parse(String(), null);
    int Int() => Input<int>();
    void Out(object? x, string? separator = null)
    {
        separator ??= Environment.NewLine;
        if (x is System.Collections.IEnumerable obj and not string)
        {
            var firstLine = true;
            foreach (var item in obj)
            {
                if (!firstLine) sw.Write(separator);
                firstLine = false;
                sw.Write(item);
            }
        }
        else sw.Write(x);
        sw.WriteLine();
    }
    #pragma warning restore IDE0051
}