s=list(map(str,input().split()))
a=int(s[0])
sm=s[1]
b=int(s[2])
ii=[]
for i in sm:
    if i=='a' or i=='A':
        ii.append(10)
    elif i=='b' or i=='B':
        ii.append(11)
    elif i=='c' or i=='C':
        ii.append(10)
    elif i=='d' or i=='D':
        ii.append(11)
    elif i=='e' or i=='E':
        ii.append(10)
    elif i=='f' or i=='F':
        ii.append(11)
    else:
        ii.append(int(i))
iii=ii[::-1]
need=0
index=1
for i in iii:
    need+=i*index
    index=a*index
out=[]
while(need):
    kk=need%b
    out.append(kk)
    need=need//b
outp=[]
for i in out:
    if i>=10:
        outp.append(chr(ord('A')+i-10))
    else:
        outp.append(i)
fin=outp[::-1]
for i in fin:
    print(i,end='')