图1-7是用14根火柴拼成的平房,要想把它变成楼房,请问至少需要移动几根火柴?
图1-7 UqqPwBA1zW3pCP8kmicnGDZ4ukBvN+ROKqaEPBEM/x1M/bvEbe5B/hVYP2eUi7+B