jin1=int(input())
qian=input()
jin2=int(input())
#任意进制转为十进制
qian=list(qian)
c = {'A': '10', 'B': '11', 'C': '12', 'D': '13', 'E': '14', 'F': '15'}
a=0
qian=[c[i] if i in c else i for i in qian]
for i in range(len(qian)):
    a+=pow(jin1,len(qian)-1-i)*int(qian[i])
cha=[]
while a>0:
    cha.append(str(a%jin2))
    a=a//jin2
cha=cha[::-1]
if jin2>10:     #列表替换操作
    c = {'10': 'A', '11': 'B', '12': 'C', '13': 'D', '14': 'E', '15': 'F'}
    cha = [c[i] if i in c else i for i in cha]
print("".join(str(x) for x in cha))