#!/usr/bin/env python
import os
import operator
from collections import defaultdict
import sys
from io import BytesIO, IOBase
import bisect

# def power(x, p):
#     res = 1
#     while p:
#         if p & 1:
#             res = res * x % 1000000007
#         x = x * x % 1000000007
#         p >>= 1
#     return res;

def main():
    n,m,k=map(int,input().split())
    A=[int(k) for k in input().split()]
    B=[int(k) for k in input().split()]
    a=[0]
    b=[0]
    for i in range(n):
        a.append(a[i]+A[i])
    for i in range(m):
        b.append(b[i]+B[i])
    ans=0
    j=m
    for i in range(n+1):
        if a[i]>k:
            break
        while b[j]>k-a[i]:
            j-=1
        ans=max(ans,i+j)
        #print(i,j)
    print(ans)

    # for _ in range(int(input())):
        # n=int(input())
        # arr=[int(k) for k in input().split()]
        # odd=[]
        # even=[]
        # for i in range(2*n):
        #     if arr[i]%2==0:
        #         even.append(i+1)
        #     else:
        #         odd.append(i+1)
        # if len(odd)%2!=0 and len(even)%2!=0:
        #     odd.pop()
        #     even.pop()
        #     for i in range(0,len(odd),2):
        #         print(odd[i],odd[i+1])
        #     for i in range(0,len(even),2):
        #         print(even[i],even[i+1])
        # else:
        #     if len(odd)!=0 and len(even)!=0:
        #         odd.pop()
        #         odd.pop()
        #         for i in range(0, len(odd), 2):
        #             print(odd[i], odd[i + 1])
        #         for i in range(0, len(even), 2):
        #             print(even[i], even[i + 1])
        #     else:
        #         for i in range(0,2*n-2,2):
        #             print(i+1,i+2)








BUFSIZE = 8192

class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


class IOWrapper(IOBase):
    def __init__(self, file):
        self.buffer = FastIO(file)
        self.flush = self.buffer.flush
        self.writable = self.buffer.writable
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
input = lambda: sys.stdin.readline().rstrip("\r\n")

if __name__ == "__main__":
    main()

Measured memory_bytes: 142044