evjeny

def r(a,b):
    al = a[-2:]
    bl = b[-2:]
    if len(a)>=2 and len(b) >=2:
        return al==bl
    return False

f = int(input())
arr = []
for i in range(4):

evjeny

def r(a,b):
    al = a[-2:]
    bl = b[-2:]
    if len(a)>=2 and len(b) >=2:
        return al==bl
    return False


def way(a,b,c,d):
    if r(a,b) and r(c,d):

evjeny

def gip(msk,adrs):
    ma = [int(i) for i in msk.split(".")]
    da = [int(i) for i in adrs.split(".")]
    res = ""
    for j in range(4):
        c = ma[j]&da[j]
        if j!=3:
            res += str(c) + "."
        else:
            res += str(c)

evjeny

def dist(ax,ay,bx,by):
    if ax==bx:
        return abs(ay-by)
    elif ay==by:
        return abs(ax-bx)
    else:
        return ((ax-bx)**2+(ay-by)**2)**0.5


def ka(ax,ay,bx,by):

evjeny

def dist(ax,ay,bx,by):
    return ((ax-bx)**2+(ay-by)**2)**0.5


def abc(ax,ay,bx,by):
    b = ay-by
    a = bx-ax
    c = -a*ay-b*bx;
    return [a,b,c]

evjeny

s = input()
lts = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
if s[0] in lts and s[1:4].isdigit() and s[4] in lts and s[5] in lts:
    print("Yes")
else:
    print("No")

evjeny

n, m, v, u = [int(i) for i in input().split()]
v -= 1
u -= 1
arr = [[0 for i in range(n)] for j in range(n)]
for i in range(m):
    a, b = [int(i) - 1 for i in input().split()]
    arr[a][b] = 1
    arr[b][a] = 1

k = int(input())

evjeny

input()
a = int(input())
i = 1
while True:
    b = a^i
    if b!=a:
        print(i,b)
        break
    i += 1

evjeny

n = int(input())
a = [int(i) for i in input().split()]
c = 0
if n==1: c = a[0]
else: c = a[0]^a[1]
i = 1
while True:
    b = c^i
    if b!=c:
        print(i,b)

evjeny

n = int(input())
a = [int(i) for i in input().split()]
c = 0
for i in a:
    c = c ^ i

i = 1
while True:
    d = c^i
    if d not in a and i not in a: