tickets.py

from collections import defaultdict
from functools import cache
from typing import DefaultDict

M = 10**9 + 7


def _get_value(a: list):
    if len(a) == 2:
        return min(a[0][0] + a[1][0], a[0][1])
    _dp = [[M for _ in range(4)] for _ in range(len(a))]
    _dp[0][1] = a[0][0]
    _dp[0][2] = a[0][1]
    _dp[0][3] = a[0][2]
    for i in range(1, len(a)):
        _dp[i][0] = min([_dp[i - k][k + 1] for k in range(1, min(i, 2) + 1)])
        for k in range(1, 4):
            _dp[i][k] = min(_dp[i - 1][0], _dp[i - 1][1]) + a[i][k - 1]
    return min(_dp[-1][0], _dp[-1][1])


t = int(input().rstrip())
a = []
for t_itr in range(t):
    row = tuple([int(x) for x in input().rstrip().split()])
    a.append(row)

print(_get_value(a))