我有这个简单的股票交易程序来计算收益或损失，当我运行程序时没有显示任何内容

The purpose of the program is to compute the gains and or losses in a simple stock market transaction and by the end the following information is needed to be displayed; number of shares, amount of purchase, amount of sell, transaction fee paid, and net profit. Here is the code that I have written thus far:The purpose of the program is to compute the ga