5 (16 решуегэ десятичные)

answ = 1000000000
for n in range(1000, 10000):
    s = str(n)
    a = int(s[0]) + int(s[1])
    b = int(s[1]) + int(s[2])
    c = int(s[2]) + int(s[3])
    l = sorted([a, b, c])
    s = str(l[1]) + str(l[2])
    if s == '1517':
        answ = min(answ, n)
print(answ)