# http://c...content-available-to-author-only...e.com/questions/54105/all-your-bijective-base-are-belong-to-us #M="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz<=>" #M="0123456789"+"".join(map(chr,range(65,91)+range(97,123)))+"<=>" #u="".join(map(chr,range(65,91)));M="0123456789"+u+u.lower()+"<=>" #M="".join(map(chr,range(48,58)+range(65,91)+range(97,123)))+"<=>" R=range;M="".join(map(chr,R(48,58)+R(65,91)+R(97,123)))+"<=>" b,s,o=input() F=M.find e=F(o)<2 B=lambda n:n and B(n/F(o)-e)+M[n%F(o)+e]or"" n=B(sum(F(s[~j])*F(b)**j for j in R(len(s)))) i=n.find('0') n=list(n) while-~i:n=n[:i-1]+[M[F(n[i-1])-1]]+[o]+n[i+1:];n=n["0"==n[0]:];i="".join(n).find('0') print"".join(n)