The answer is 91
+ K4 i( B* \, m7 ~% [4 Y1 row 3x4+1x3=155.39.217.77: V7 e7 Y% `; _1 E( r/ _
2 row 4x5+2x4=28tvb now,tvbnow,bttvb+ F8 s+ d1 e- R+ B: f& d. K v3 v
3 row 5x6+3x5=455.39.217.77: ~* c: {9 x$ N7 X$ r: h. i: \
4 row 6x7+4x6=66
; ]' D' Z/ C2 q! j9 W5 J- etvb now,tvbnow,bttvb5 row 7x8+5x7=91  |