make learning more interactive and fun for students, a math teacher decides to teach a concept to students by using Lego blocks. There are $2$ rows of legos, rowA $($of length n$)$ and rows $($of length m$).$ Both rows hold legos with positive integer values printed on them. However, some values $($possibly$,$ none$)$ are missing. The missing values are denoted by $0.$ Students need to incorporate the missing values. The task is to replace each $0$ with a positive integer such that the sums of both arrays are equal. Return the minimum sum possible. If it is not possible to make the sums equal, return $-1.$