1.3

a = input()

bracket_1 = 0
bracket_2 = 0
bracket_3 = 0

i = 0
check = 0

while check == 0:

    if a[i] == "(":
        bracket_1 += 1

        if a[i + 1] == ']' or a[i + 1] == '}':
            print("false")
            break

    if a[i] == ")":
        bracket_1 -= 1

    if a[i] == "[":
        bracket_2 += 1
        if a[i + 1] == ')' or a[i + 1] == '}':
            print("false")
            break

    if a[i] == "]":
        bracket_2 -= 1

    if a[i] == "{":
        bracket_3 += 1
        if a[i + 1] == ']' or a[i + 1] == ')':
            print("false")
            break

    if a[i] == "}":
        bracket_3 -= 1

    if bracket_1 < 0 or bracket_2 < 0 or bracket_3 < 0:
        print("false")
        break


    i+=1

    if i+1 == len(a):

        if a[i] == "(":
            bracket_1 += 1

        if a[i] == ")":
            bracket_1 -= 1

        if a[i] == "[":
            bracket_2 += 1

        if a[i] == "]":
            bracket_2 -= 1

        if a[i] == "{":
            bracket_3 += 1

        if a[i] == "}":
            bracket_3 -= 1

        if bracket_1 < 0 or bracket_2 < 0 or bracket_3 < 0:
            print("false")
            break
        check = 1


if bracket_1 == 0 and bracket_2 == 0 and bracket_3 == 0 :
    print("true")