HI, Can someone PLEASE HELP!!!!!!!!!!!!!!!!!

I am using the following count to count how many time a number above 70 is
input, I need to add M or F onto the end of the numbers. e.g. 74M, the
formula i'm using does not recognise both number and text.

this is the formula i'm using: =COUNTIF(Interventions!C19:C81,"70")

I need to add a letter M and F onto the end of this formula to recognise
input of e.g. 74M, 86M, 95F to place in correct cells on a different
worksheet.

70+ Males for M & 70+ Females for F

Can anyone HELP!!!!!!!! Its doing my head in...

Thanks