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

namespace Atcoder
{
    public class Program
    {
        private static long mod = 1000000007;
        private static long max = 999999999999;

        static void Main(string[] args)
        {
            var r = ReadSplit();
            var n = r[0].Int();
            var m = r[1].Int();
            var k = r[2].Long();
            var r2 = ReadSplit();
            var r3 = ReadSplit();

            var la = new long[n + 1];
            var lb = new long[m];
            var rb = new long[m + 1];
            for (int i = 0; i < n; i++)
            {
                la[i + 1] = r2[i].Long();
            }

            for (int i = 0; i < m; i++)
            {
                lb[i] = r3[i].Long();
                rb[i + 1] += rb[i] + lb[i];
            }

            var at = 0L;
            var ans = 0L;
            for (int i = 0; i <= n; i++)
            {
                at += la[i];
                var left = -1;
                var right = rb.Length - 1;
                if (k - at < 0) break;
                if (rb[1] > k) continue;
                var mid = 0;
                while (right - left > 1)
                {
                    mid = left + (right - left) / 2;
                    if (rb[mid] >= k - at)
                    {
                        right = mid;
                    }
                    else left = mid;
                }
                if (rb[right] > k - at)
                {
                    right = left;
                }
                ans = Math.Max(ans, right + i);
            }
            WriteRead(ans);
        }

        public static string Read()
        {
            return Console.ReadLine();
        }

        public static string[] ReadSplit()
        {
            return Console.ReadLine().Split(' ');
        }

        public static void WriteRead(object str)
        {
            Console.WriteLine(str);
            Read();
        }

        public static void Write(object str)
        {
            Console.WriteLine(str);
        }

        private static bool ChangeMin<T>(ref T a, T b) where T : IComparable
        {
            if (a.CompareTo(b) > 0)
            {
                a = b;
                return true;
            }
            return false;
        }

        private static bool ChangekMax<T>(ref T a, T b) where T : IComparable
        {
            if (b.CompareTo(a) > 0)
            {
                a = b;
                return true;
            }
            return false;
        }
    }
}


public static class Extentions
{
    public static int Int(this object obj)
    {
        return int.Parse(obj.ToString());
    }

    public static long Long(this object obj)
    {
        return long.Parse(obj.ToString());
    }

    public static decimal Decimal(this object obj)
    {
        return decimal.Parse(obj.ToString());
    }

    public static double Double(this object obj)
    {
        return double.Parse(obj.ToString());
    }

    public static T2 GetValueZero<T1, T2>(this Dictionary<T1, T2> d, T1 key) where T2 : struct
    {
        T2 value;
        if (d.TryGetValue(key, out value))
        {
            return value;
        }
        return new T2();
    }
}



Measured memory_bytes: 59620