Question: Olivia Newton-John has how many more Grammy wins than the number of performers in the Main Event Tour?

Context paragraphs:
The Main Event (video): The Main Event is a video, released in 1999, of a tour The Main Event Tour by singers Olivia Newton-John, John Farnham and Anthony Warlow.

Physical Tour: The Physical Tour was the fifth concert tour by Australian singer Olivia Newton-John, in support of her 12th studio album, "Physical" (1981).  The tour consisted of 64 shows in North America only, the second largest by Newton-John, visiting arenas and stadiums.  It's the first concert tour by Newton-John since 1978 and her last in 16 years, until The Main Event Tour.

Olivia Newton-John: Olivia Newton-John, (born 26 September 1948) is an Australian singer, songwriter, actress, entrepreneur and activist.  She is a four-time Grammy award winner who has amassed five number-one and ten other top ten "Billboard" Hot 100 singles, and two number-one "Billboard" 200 solo albums.  Eleven of her singles (including two platinum) and fourteen of her albums (including two platinum and four double platinum) have been certified gold by the RIAA.  She has sold an estimated 100 million records worldwide, making her one of the world's best-selling artists of all time.  She starred in the musical film "Grease", and is one of the most successful in history, with the single You're the One That I Want, with John Travolta, one of the best selling singles.

Olivia Newton-John's Greatest Hits: Olivia Newton-John's Greatest Hits (1977) was the first compilation album released by Olivia Newton-John in the United States.  (In some other regions, Newton-John released a 1974 compilation, "First Impressions".  This album was therefore marketed instead as "Greatest Hits Vol.  2" and featured a different track listing.)  The album collected all of Newton-John's American Top 40 singles released between 1971 and 1977.  "Changes" was the only track not released as a single, but it was one of Newton-John's first self-written songs that she recorded.  The album was Newton-John's first platinum certification peaking No. 13 Pop and No. 7 Country.  It ended up being certified double Platinum in the US and Platinum in the UK and Canada, and also Gold in Hong Kong.

If Not for You (album): If Not for You is the debut studio album by British-Australian singer-songwriter Olivia Newton-John, released in November 1971 by Festival Records.  The album was released on the Pye International label in the UK as "Olivia Newton-John", with a slightly different cover.  As a covers album, "If Not for You" features mostly songs previously recorded from contemporary artists of the 1960s and early 1970s.  She made several performances to promote "If Not for You" and her follow-up album, "Olivia", including an international tour with British singer Cliff Richard.  It was her first album released by Festival Records, which would release all her albums in Australia until its dissolution in 2005.  It also has Newton-John's first works with her long-time musical partner, John Farrar.

A Summer Night with Olivia Newton-John: A Summer Night with Olivia Newton-John was the eighteenth concert tour by Australian singer Olivia Newton-John, in support of her sixth soundtrack "A Few Best Men".  The tour name drifts from her 1978 hit, "Summer Nights", from the musical film "Grease".  It is Newton-John largest tour since the Heartstrings World Tour, which runs from 2002 to 2005.  It was her first tour in the United Kingdom in over 30 years.

Highlights from The Main Event: Highlights from The Main Event is an Australian live album released in 1998, which consists of performances from the collaborative The Main Event Tour by John Farnham, Olivia Newton-John, and Anthony Warlow.  The album peaked at No. 1 on the ARIA Albums Chart for two weeks in December that year.  It was re-released in 2001 with three additional tracks.

Olivia's Greatest Hits Vol. 2: Olivia's Greatest Hits Vol.  2 is the second hits collection from English-born, Australian pop singer Olivia Newton-John released in September 1982.  The album compiled most singles released by Newton-John since the release of her 1977 "Olivia Newton-John's Greatest Hits" album from her following albums and soundtracks.  The album included two new recordings; "Heart Attack" and "Tied Up".  Both songs were released as singles and reached number 3 and 38 on the pop charts, respectively.  "Heart Attack" was a number one single in France.

The Main Event (1998 concert tour): The Main Event Tour was a 1998 joint concert tour by Australian singers John Farnham, Olivia Newton-John and Anthony Warlow.

Magic: The Very Best of Olivia Newton-John: Magic: The Very Best of Olivia Newton-John is a 2001 greatest hits compilation from Olivia Newton-John.  This was the first compilation from Newton-John to include all 15 of her Top 10 hits on the "Billboard" Hot 100 and the first Newton-John album to include "The Grease Megamix".

Supporting paragraphs: The Main Event (1998 concert tour) Olivia Newton-John
Answer: One