x,y,s=input().split()
x=int(x)
y=int(y)
if s=='0':
    print(0)
t=0
now=1
for i in range(len(s)-1,-1,-1):
    if s[i]>='0' and s[i]<='9':
        t=t+now*int(s[i])
    elif s[i]>='A' and s[i]<='Z':
        t=t+now*(ord(s[i])-65+10)
    else :
        t=t+now*(ord(s[i])-97+36)
    now=now*x
ans=''
while t :
    if t%y<=9:
        ans=ans+chr(t%y+48)
    elif t%y<=35:
        ans=ans+chr(t%y-10+65)
    else :
        ans=ans+chr(t%y-36+97)
    t=t//y
for i in range(len(ans)-1,-1,-1):
    print(ans[i],end='')