beyond day $15.$

$\backslash$begin$\{$tabular$\}\{$cccccc$\}$

$\backslash$hline Activity & $\backslash$begin$\{$tabular$\}\{$c$\}$

Normal $\backslash \backslash$

Time $($days$)$

$\backslash$end$\{$tabular$\}$ & Normal Cost $(\backslash$$$)$ & $\backslash$begin$\{$tabular$\}\{$c$\}$

Crash $\backslash \backslash$

Time $($days$)$

$\backslash$end$\{$tabular$\}$ & $\backslash$begin$\{$tabular$\}\{$c$\}$

Crash Cost $\backslash \backslash$

$(\backslash$$$)$

$\backslash$end$\{$tabular$\}$ & Immediate Predecessor$($s$)\backslash \backslash$

$\backslash$hline A & $4$ & $800$ & $3$ & $1,000$ & $-\backslash \backslash$

B & $5$ & $1,000$ & $3$ & $2,200$ & $-\backslash \backslash$

C & $5$ & $500$ & $3$ & $1,500$ & A$,$ B $\backslash \backslash$

D & $3$ & $1,200$ & $2$ & $1,500$ & B $\backslash \backslash$

E & $4$ & $1,500$ & $4$ & $1,500$ & C$,$ D $\backslash \backslash$

F & $2$ & $1,300$ & $1$ & $1,400$ & E $\backslash \backslash$

G & $3$ & $900$ & $1$ & $1,000$ & E $\backslash \backslash$

H & $5$ & $300$ & $3$ & $500$ & G $\backslash \backslash$

$\backslash$hline

$\backslash$end$\{$tabular$\}$

a$.$ What is the project's duration if only normal times are used?

The project duration is day$($s$).($Enter your response as an integer.$)$