An exterior beam, located in Toronto, with a rectangular cross section has a width of $700$mm$,$ height of $800$mm and consists of $12-25$M bars, and $10$M stirrup. Given that the spacing between the bars is $35$mm$,$ how many layers would you need to fit the bars in and what is the minimum required width value?

f$$c $=25$ MPa

fy $=400$ MPa

Es $=200$GPa

Maximum aggregate size: $20$mm

Minimum required Width value $=$ Blank $1$ mm

# of layers $=$ Blank $2$