Please help work below facts into the estate tax formula for John Doe, who died June 17, 2023. John (born July 2, 1940) resided at 30 Rockefeller Plaza, New York, NY 10112 and was a lifelong NY resident. His first wife, Jane Doe, passed away in 2005. In 2010, he married Eliza Smith, a U.S. citizen, who survives him. John has three children (Amy, Brady, and Candy Doe), who also survive him, from his first marriage to Jane Doe.

The following properties were discovered upon John's death, listed below at date of death values.

• Primary residence with a value of $850,000. This was purchased by John in 2012 and titled in the names of John Doe and Eliza Smith, joint tenants with right of survivorship. How much of this residence value is included in John's gross estate? Isn't it 50% deemed contribution rule between spouses so $425,000?