При нажатии на кнопку закрывается приложение и вылазит ошибка: Process finished with exit code -1073740791 (0xC0000409)

# -*- coding: utf-8 -*-
 
# Form implementation generated from reading ui file 'C:\Python\lite.ui'
#
# Created by: PyQt5 UI code generator 5.15.6
#
# WARNING: Any manual changes made to this file will be lost when pyuic5 is
# run again.  Do not edit this file unless you know what you are doing.
 
 
from PyQt5 import QtCore, QtGui, QtWidgets
 
 
class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName("Dialog")
        Dialog.resize(700, 500)
        self.st_a = QtWidgets.QLabel(Dialog)
        self.st_a.setGeometry(QtCore.QRect(10, 20, 16, 16))
        self.st_a.setObjectName("st_a")
        self.st_b = QtWidgets.QLabel(Dialog)
        self.st_b.setGeometry(QtCore.QRect(10, 90, 16, 16))
        self.st_b.setObjectName("st_b")
        self.btn = QtWidgets.QPushButton(Dialog)
        self.btn.setGeometry(QtCore.QRect(10, 210, 150, 50))
        self.btn.setObjectName("btn")
        self.line = QtWidgets.QLineEdit(Dialog)
        self.line.setGeometry(QtCore.QRect(70, 360, 161, 50))
        self.line.setObjectName("line")
        self.sta = QtWidgets.QTextEdit(Dialog)
        self.sta.setGeometry(QtCore.QRect(30, 10, 100, 50))
        self.sta.setObjectName("sta")
        self.stb = QtWidgets.QTextEdit(Dialog)
        self.stb.setGeometry(QtCore.QRect(30, 90, 100, 50))
        self.stb.setObjectName("stb")
 
        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)
 
 
        self.btn.clicked.connect(self.bp)
 
    def retranslateUi(self, Dialog):
        _translate = QtCore.QCoreApplication.translate
        Dialog.setWindowTitle(_translate("Dialog", "Dialog"))
        self.st_a.setText(_translate("Dialog", "a"))
        self.st_b.setText(_translate("Dialog", "b"))
        self.btn.setText(_translate("Dialog", "PushButton"))
 
    def bp(self):
        a = int(self.sta.text())
        b = int(self.stb.text())
        s = a * b
        self.line.setText(str(s))
 
 
if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    Dialog = QtWidgets.QDialog()
    ui = Ui_Dialog()
    ui.setupUi(Dialog)
    Dialog.show()
    sys.exit(app.exec_())