print("请选择想要进行的运算！")
n1 = int(input("请输入计算数1："))
m = input("请输入运算符:")
while(m != "="):
    if m == '+':
        n2 = int(input("请输入计算数2:"))
        n3 = n1+n2
        break
    elif m == '-':
        n2 = int(input("请输入计算数:2"))
        n3 = n1-n2
        break
    elif m== '*':
        n2 = int(input("请输入计算数2:"))
        n3 = n1*n2
        break
    elif m == '/':
        n2 = int(input("请输入计算数2:"))
        if n2 == 0:
            print("输入错误，请重新输入！")
        else:
            n3 = n1/n2
            break
    elif m == '%':
        n2 = int(input("请输入计算数2:"))
        if n2 == 0:
            print("输入错误，请重新输入！")
        else:
            n3 = n1%n2
            break
print("结果为：",n3)