import sys
from collections import deque

def main():
    K, N = map(int, sys.stdin.readline().split())
    A = list(map(int, sys.stdin.readline().split()))
    B = list(map(int, sys.stdin.readline().split()))
    M = max(B)
    
    # Check if any initial term is >= M
    if any(a >= M for a in A):
        if N < K:
            print(A[N])
        else:
            print(M)
        return
    
    # If N is within the initial terms
    if N < K:
        print(A[N])
        return
    
    # Simulate the sequence until N or until a term >= M is found
    current = deque(A)
    for i in range(K, N + 1):
        new_term = max(min(current[m], B[m]) for m in range(K))
        current.popleft()
        current.append(new_term)
        if new_term >= M:
            print(M)
            return
    print(current[-1])

if __name__ == "__main__":
    main()