Jump on collision problem

Hi,

I have a ragdoll and I want it to jump when its feet touch the ground like this :

 float jumpForce = 100;
 
 void OnCollisionEnter2D(Collision2D col)
 {
    if(col.gameObject.tag == "Ground")
    {
       rigidbody2D.velocity = new Vector2 (0, jumpForce);
    }
 }

The problem occurs when both feet touch the ground, it jumps twice (which is normal because the script is the same for both feet).

I just want one jump :

foot1 touches the ground : JUMP 1x OR foot2 touches the ground : JUMP 1x

if both touch the ground : JUMP 1x

How can I implement that ? It sounds so easy but I can't do it. Thanks.