The answer is 91
* Y3 ^; a5 c$ Y: R( J8 B6 Gtvb now,tvbnow,bttvb1 row 3x4+1x3=15! f0 t s! N+ k7 V
2 row 4x5+2x4=285.39.217.778 k6 a/ `: `# p" [. j
3 row 5x6+3x5=45
0 a4 t, u. _( }! {" T4 ^! o" Otvb now,tvbnow,bttvb4 row 6x7+4x6=665.39.217.77; F7 z. t% w. \( g8 T
5 row 7x8+5x7=91  |