import sys
sys.setrecursionlimit(10000)

f=lambda n,k=2,m=1,s='':-~s.find(`n`)or f(n,k+1,m*k*k,s+m%k*`k`)

for n in 13, 997, 999, 314:
	print '%3u -> %4u' % (n, f(n))