670
That design , by the late chief engraver , Christian Gobrecht , following a concept by Thomas Sully and Titian Peale , was first used in 1836 and by 1840 was on all denominations of silver coins then being struck .
 person: Christian Gobrecht; person: Thomas Sully; person: Titian Peale
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 person: Christian Gobrecht; person: Thomas Sully; person: Titian Peale