杨辉三角的变形

def solve(n):
    n = int(n)
    if n == 1 or n == 2:
        print(-1)
    else:
        row = [1, 1, 1]
        for i in range(3, n + 1):
            new_row = [1]
            for j in range(len(row) - 1):
                new_row.append(row[j] + row[j + 1])
            new_row.append(1)
            row = new_row
        for i, v in enumerate(row):
            if v % 2 == 0:
                print(i + 1)
                return
        print(-1)