try:
while True:
#輸入資料
left_link = input().replace('L:', '').replace('\n', '').replace('\r', '')
right_link = input().replace('R:', '').replace('\n', '').replace('\r', '')
location = input().replace('\n', '').replace('\r', '')
rule = input().replace('\n', '').replace('\r', '')
#利用字典修正重複的連結
dic_left_link = {}
dic_right_link = {}
#利用字典的key對應到value，紀錄達到轉盤從輸送帶(key)轉移到下一個輸送帶(value)
for x in range(len(left_link)-1):
dic_left_link[left_link[x]] = left_link[x+1]
for x in range(len(right_link)-1):
dic_right_link[right_link[x]] = right_link[x+1]
#直接判斷規則，為R或L，在藉由字典的key連結到下一個輸送帶上
for x in range(len(rule)):
if rule[x] == 'L':
try:
dic_left_link[location]
except KeyError:
pass
else:
location = dic_left_link[location]
if rule[x] == 'R':
try:
dic_right_link[location]
except KeyError:
pass
else:
location = dic_right_link[location]
print(location)
except EOFError:
pass
