while True: try: inp=input().strip() #print(inp) lenth=len(inp) #print(lenth) #max_num=1 list1=[] for i in range(lenth-1,0,-1): for j in range(lenth-i): index1=inp[j:j+i] list1.append(index1) #print(list1) result=0 for i in list1: if list1.count(i)>1: result=len(i) break print(result) except: break