A young boy with a creative mind decided to build a kite. He started with 37 paper straws but decided that 4 were unnecessary and removed them. Later, he realized his kite was still too bulky and removed another 23 straws. He multiplied the remaining number of straws by 45, subtracted 49 from that total, and then took out 7 more straws. How many straws did the boy have left?