you organize cycling race street city the city contain n junction pair connect road road direction no road connect pair intersection road connect intersection itselfyou want race open professional athlete beginner cyclist that s organize race nomination easy moderate difficult participant choose suitable nomination for nomination choose route chain junction consecutively connect road route meet follow condition route start intersection finish intersection place start finish can not avoid collision route common junction common start finish road irrespective drive direction road route route pass twice intersection visit road twice irrespective drive direction road second time visitprepare competition begin need determine route race quickly possible the length route important important give requirement meet