x =['l','e','a','d','i','n','g','u','n','i','v','e','r','s','i','t','y']
x.sort()
s = input()
li = []
y = len(s)
for i in range(y):
    li.append(s[i])
li.sort()
if li == x:
    print("Leading University")
else:
    print("Impossible")