N=int(input())
while True:
    change=False
    S=str(N)
    for i in range(len(S)):
        if S[i]=='3':
            change=True
            T=S[:i]
            U=S[i:]
            UU=int(U)
            UU-=1
            S=T+str(UU)
            #S[i]='2'
            #for j in range(i+1,len(S)):
                #S[i]='9'
            break

    
    N=int(S)
    if N%3==0:
        change=True
        N-=1
    if change==False:
        print(N)
        break