1 2 3 4 5 6 7 n = int(raw_input().strip()) for i in range(n/7,-1,-1): if (n-7*i)%4==0: print '4'*((n-7*i)/4)+'7'*i break if i==0 and (n-7*i)%4<>0: print -1
1 2 3 4 5 6 7
n = int(raw_input().strip()) for i in range(n/7,-1,-1): if (n-7*i)%4==0: print '4'*((n-7*i)/4)+'7'*i break if i==0 and (n-7*i)%4<>0: print -1