How do I format JSON for multiple signers but I only need 1 on them to sign?

I need to send an email to multiple people using the POST Aggreements and I only need one of them to sign. Basically send 1 document to 2 or more people and any of them can sign.

I cannot seem to format the "participantSetsInfo" right after a bunch of attempts.

This is the API using and I'm using V6
https://api.na2.adobesign.com:443/api/rest/v6/agreements

I thought I was close but this did not work either. 

"participantSetsInfo": [
{
"memberInfos": [
{
"email": "abc@gmail.com"
}
],
"order": 1,
"role": "SIGNER"
},
{
"memberInfos": [
{
"email": "def@gmail.com"
}
],
"order": 1,
"role": "SIGNER"
}
],

Any help is greatly appreciated. Thank you ahead of time.