Using Countx or other appropriate dax formula

Dear All,

I have the table, 

I have created a measure:

TotalMedal = COUNTX(summer;summer[Medal])

 and when I tried to count the number of gold, silver and bronze seperately, I getting same result as totalMedal.

the formula use for silver was: TotalMedal = COUNTX(summer;summer[Medal])

My objective is to get total number of Medals. I also want to calculate number of gold, silver and bronze. Please help!!!!!