费尽心思

to rack one's brains (idiom); to take great pains to think sth through

surname Fei

to cost / to spend / fee / wasteful / expenses

to the greatest extent / (when used before a noun of location) furthest or extreme / to be within the limits of / to give priority to

to use up / to exhaust / to end / to finish / to the utmost / exhausted / finished / to the limit (of sth) / all / entirely

with all of one's heart

heart / mind / intention / center / core / CL:顆|颗[ke1],個|个[ge4]

mind / thoughts / inclination / mood

to think / to consider