import sys def str_add(a, b): a, b = a[::-1], b[::-1] if len(a) < len(b): a, b = b, a length = len(a) b = b + '0'*(length - len(b)) res = '' c = 0 for i in range(length): c, rmd = divmod(int(a[i]) + int(b[i]) + c, 10) res += str(rmd) if c > 0: res += str(c) return res[::-1] raw_input = [] for ...