# This is my first code in python. (So, the code is too dirty.)
# I don't know that this calculator works exactly.

# +----------------------+
# | This is a calculator |
# +----------------------+
#
# Enter the calculate formula
#
# => 1 + 3 / 4
#
# The answer is: 1.75

class colors:
    OKBLUE = '\033[94m'
    OKCYAN = '\033[96m'
    OKGREEN = '\033[92m'
    WARNING = '\033[93m'
    ENDC = '\033[0m'
    BOLD = '\033[1m'

def calculator():
    print("\n+----------------------+")
    print("| " + colors.WARNING + "This is a calculator" + colors.ENDC + " |")
    print("+----------------------+\n")
    formula = (input("Enter the calculate formula\n\n=> "+ colors.OKCYAN)).split(" ")
    array = []
    for i in range(len(formula)):
        if (formula[i] == "x"):
            array.append(i)
        elif (formula[i] == "/"):
            array.append(i)
    n = 0
    for i in range(len(array)):
        r = 0
        if (formula[array[i] - n] == "x"):
            r = float(formula[array[i] - 1])*float(formula[array[i] + 1])
            formula.pop(array[i] - 1 - n)
            formula.pop(array[i] - 1 - n)
            formula.pop(array[i] - 1 - n)
            formula.insert(array[i] - 1 - n, r)
            n = n + 2
        elif (formula[array[i] - n] == "/"):
            r = float(formula[array[i] - 1 - n])/float(formula[array[i] + 1 - n])
            formula.pop(array[i] - 1 - n)
            formula.pop(array[i] - 1 - n)
            formula.pop(array[i] - 1 - n)
            formula.insert(array[i] - 1 - n, r)
            n = n + 2
    array = []
    for i in range(len(formula)):
        if (formula[i] == "+"):
            array.append(i)
        elif (formula[i] == "-"):
            array.append(i)
    n = 0
    for i in range(len(array)):
        r = 0
        if (formula[array[i] - n] == "+"):
            r = float(formula[array[i] - 1 - n])+float(formula[array[i] + 1 - n])
            formula.pop(array[i] - 1 - n)
            formula.pop(array[i] - 1 - n)
            formula.pop(array[i] - 1 - n)
            formula.insert(array[i] - 1 - n, r)
            n = n + 2
        elif (formula[array[i] - n] == "-"):
            r = float(formula[array[i] - 1 - n])-float(formula[array[i] + 1 - n])
            formula.pop(array[i] - 1 - n)
            formula.pop(array[i] - 1 - n)
            formula.pop(array[i] - 1 - n)
            formula.insert(array[i] - 1 - n, r)
            n = n + 2
    print(colors.OKGREEN + "\nThe answer is:" + colors.BOLD, formula[0], colors.ENDC, "\n")

calculator()