How do you get to the 4th gym badge from vermilon city in Pokemon leaf green?

find flash on route 2 your Pokemon should know cut go to route 9 and use cut go to the rock tunnel and come and go left from lavender townand at the end of that route go to the little house and go downthe underground path and go to celedon and go south

find flash on route 2 your Pokemon should know cut go to route 9 and use cut go to the rock tunnel and come and go left from lavender townand at the end of that route go to the little house and go downthe underground path and go to celedon and go south