Ruudukko

n = int(input())
grid = [input() for _ in range(n)]
 
routes = [[(0, 0)]]
cur_seq = [ord(grid[0][0])]
 
for i in range(2*(n-1)):
    cur_seq += [999]
    new_routes = []
    for route in routes:
        (x, y) = route[-1]
        if x == n - 1:
            y += 1
        elif y == n - 1:
            x += 1
        else:
            if ord(grid[y + 1][x]) > ord(grid[y][x+1]):
                x += 1
            else:
                y += 1;
        c = ord(grid[y][x])
        route += [(x, y)]
        if c < cur_seq[-1]:
            cur_seq[-1] = c
            new_routes = [route]
        elif c == cur_seq[-1]:
            new_routes += route
 
print("".join(chr(c) for c in cur_seq))

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: WRONG ANSWER

Test 8

Group: 2

Verdict: WRONG ANSWER

Test 9

Group: 2

Verdict: WRONG ANSWER

Test 10

Group: 2

Verdict: WRONG ANSWER

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: WRONG ANSWER

Test 13

Group: 3

Verdict: WRONG ANSWER

Test 14

Group: 3

Verdict: WRONG ANSWER

Test 15

Group: 3

Verdict: WRONG ANSWER