Formula error

Dear friends,
In cell ‘BE8’ I want to insert this formula but it is giving error ‘missing parentheses. It’s a result sheet and the terms are as follows:

If the student is fail in 1 subject (<35) then the remark should be ‘F1’
If the student is fail in 2 subject (<35) then the remark should be ‘F2’
If the student is fail in 3 subject (<35) then the remark should be ‘F3’
If the student is fail in 4 subject (<35) then the remark should be ‘F4’
If the student is fail in 5 subject (<35) then the remark should be ‘F5’
If the student is fail in 6 subject (<35) then the remark should be ‘F6’

The formula is:

=countif(IF(AND(j8 < 35, n8 < 35, r8 < 35, v8 < 35, z8 < 35, ad8 < 35=1, "F1", countif(IF(AND(j8 < 35, n8 < 35, r8 < 35, v8 < 35, z8 < 35, ad8 < 35=2, "F2", countif(IF(AND(j8 < 35, n8 < 35, r8 < 35, v8 < 35, z8 < 35, ad8 < 35=3, "F3", countif(IF(AND(j8 < 35, n8 < 35, r8 < 35, v8 < 35, z8 < 35, ad8 < 35=4, "F4", countif(IF(AND(j8 < 35, n8 < 35, r8 < 35, v8 < 35, z8 < 35, ad8 < 35=5, "F5", countif(IF(AND(j8 < 35, n8 < 35, r8 < 35, v8 < 35, z8 < 35, ad8 < 35=6, "F6", "P all")

Please suggest me a correction.

Thanking you.

Sincerely,

Mukesh