str1 = '1 2 3 4 5 6 7 8 9 0 + - * / ) ( ] [ } {' x1 = input() for word in x1: if word not in str1: print('error') break else: x1 = x1.replace('[','(') x1 = x1.replace(']',')') x1 = x1.replace('{','(') x1 = x1.replace('}',')') res = eval...