Struggling with a task with brackets

Question

The task is to change brackets (operations, numbers and their positions should be remained the same) to make $F$ equal to $850$.

$F = (1 + 2) \times (3 + 4) \times (5 + 6) \times (7 + 8) \times (9 + 10) \times (11 + 12) \times (13 + 14) + 15$

Answer 1

$\\((1+2)*(3+4))*5 + (6*7+8)*9+10*11+12*13+14+15=F$

$\\21*5+50*9+110+156+14+15=F$

$\\105+450+110+156+14+15=850$

Answer 2

Another way: $$1+2∗(3+4∗5+6∗7+8∗9+10∗11+12∗13+14)+15=F$$ $$1+2*417+15=850$$