Validating Cell if there is same info

Question

Hello guys I have 1 question How Can i check cell if there is same Data or not . For Example here you see that there are many 2550000 so i want to code that checks this row and see if there is more than 4 same info just MessageBox.Show("there are too many same data"+(the data what is too many));
plz if you can help me out of this solution thnx anyway