def data1(m,x): lenth=len(x) res=0 for i in range(lenth): res+=int(list1.index(x[i]))*m**(lenth-1-i) return res def data2(n,x): re=[] if x==0: return 0 else: while x!=0: x,res=divmod(x,n) re.append(str(list1[res])) return ''.join(re[::-1]) while True: try: list1=['0','1','2','3','4','5','6','7','8','9', 'A','B','C','D','E','F', 'G','H','I','J','K','L', 'M','N','O','P','Q','R', 'S','T','U','V','W','X', 'Y','Z'] m,n=map(int,input().strip().split(' ')) x=list(input().strip()) #print(data1(m,x)) result=data2(n,data1(m,x)) print(result) except: break