Преобразование строки в Python?

ValueError: invalid literal for int() with base 10: '−1'

lst = []
with open("input.txt") as file:
    for line in file.readlines():
        lst.extend(line.rstrip().split(' '))
print(lst)

lst_int = [int(i) for i in lst]

3 −1
2 2
1 2 3 4
2 2
5 6 7 8
1 2
3 8
2 2
1 0 0 2
1 2
1 5