### BUGGY CODE ###

#!/usr/bin/env python3
import sys

def solve(N: int, M: int, K: int, A: "List[int]", B: "List[int]"):
    if sum(A) + sum(B) < K:
        print(N + M)
        return
    weightA = 0
    tmp_A = N
    for idx, a in enumerate(A):
        if weightA + a > K:
            tmp_A = idx
            break
        else:
            weightA += a
    max_count = current_count = tmp_A
    len_A = tmp_A

    weightB = 0
    terminated = False
    for b in B:
        if terminated == True and weightA + weightB > K:
            break

        if len_A==0 and weightA + weightB + b > K:
            break

        if weightA + weightB + b <= K:
            weightB += b
            current_count += 1

        elif terminated==False:
            while weightA + weightB + b > K:
                if len_A>0:
                    weightA -= A[len_A-1]
                    len_A -= 1
                    current_count -= 1
                else:
                    terminated=True

            if weightA + weightB + b <= K:
                weightB += b
                current_count += 1
        max_count = max(max_count, current_count)


    print(max_count)
    return


def solve_old(N: int, M: int, K: int, A: "List[int]", B: "List[int]"):
    weightA = 0
    tmp_A = N
    for idx, a in enumerate(A):
        if weightA + a > K:
            tmp_A = idx
            break
        else:
            weightA += a
    max_count = current_count = tmp_A
    len_A = tmp_A

    weightB = 0
    terminated = False
    for b in B:
        if terminated == True and weightA + weightB > K:
            break

        if len_A==0 and weightA + weightB + b > K:
            break

        if weightA + weightB + b <= K:
            weightB += b
            current_count += 1

        elif terminated==False:
            while weightA + weightB + b > K:
                if len_A>0:
                    weightA -= A[len_A-1]
                    len_A -= 1
                    current_count -= 1
                else:
                    terminated=True

            if weightA + weightB + b <= K:
                weightB += b
                current_count += 1
        max_count = max(max_count, current_count)

    print(max_count)
    return


# Generated by 1.1.7.1 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    M = int(next(tokens))  # type: int
    K = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    B = [int(next(tokens)) for _ in range(M)]  # type: "List[int]"
    solve(N, M, K, A, B)

if __name__ == '__main__':
    main()


### FIXED CODE ###

#!/usr/bin/env python3
import sys


N, M, K = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
a, b = [0], [0]

for i in range(N):
    a.append(a[i] + A[i])
for i in range(M):
    b.append(b[i] + B[i])
ans, j = 0, 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(ans)