A massless string of length $l$ passes over a frictionless pulley whose axis is horizontal. Two monkeys hang from the ends of the string at the same distance $l/2$ from the pulley, the monkeys start climbing upward simultaneously. First monkey climbs with a speed v relative to the string and the second with a speed $2v$. Both monkeys have equal masses. Then the time taken by the first and second monkey is meeting each other are respectively