def Divisor_Counts(N,inf=float("inf")): divisor_counts=[inf]+[1]*N for p in range(2,N+1): if divisor_counts[p]!=1: continue pp=p e=1 while pp<=N: for i in range(pp,N+1,pp): divisor_counts[i]+=divisor_counts[i]//e e+=1 pp*=p return divisor_counts X=int(input()) inf=1<<60 D=Divisor_Counts(X,inf) f=[N-D[N] for N in range(X+1)] mi,ans_lst=inf,[] for A in range(1,X): B=X-A if abs(f[A]-f[B])