1000
tk mik nha, mik tk ban r day
250+250+250+250=250*4
=1000
250+250+250+250=500+500
=1000
250 + 250 + 250 + 250
= 500 + 250 + 250
= 750 + 250
= 1000
250 + 250 + 250 + 250
= 500 + 250 + 250
= 750 + 250
= 1000
250 + 250 + 250 + 250
= 500 + 250 + 250
= 750 + 250
= 1000
250 + 250 + 250 + 250 = 250 x 4 = 1000