Ruudukko

n = int(input())
# 'A' <= 'B'

letters = tuple(input() for i in range(n))


routes = [[0] * (n) for _ in range(n)]
routes[0] = [letters[0][:i + 1] for i in range(n)]
for i in range(1, n):
    routes[i][0] = routes[i - 1][0] + letters[i][0]
    for j in range(1, n):
        routes[i][j] = min(routes[i - 1][j], routes[i][j - 1]) + letters[i][j]

# print(routes)
print(routes[-1][-1])

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: RUNTIME ERROR

Test 12

Group: 3

Verdict: RUNTIME ERROR

Test 13

Group: 3

Verdict: RUNTIME ERROR

Test 14

Group: 3

Verdict: RUNTIME ERROR

Test 15

Group: 3

Verdict: RUNTIME ERROR