$(1)$ Array index starts with what number? $(2$ points$)$

$(2)$ Solve $($hand calculate$)$ the output $"$y$"$ from the following program. $(3$ points$)$

$(3)$ Show the manual process and calculation how you get the output. $(5$ points$)$

int i$,$ j$,$ y $=0,$ x$[3][3]=\{\{1,2,4\},\{8,16,32\},\{64,128,256\}\}$;

for $($i $=1$; i $<10$; i $+=4)$

$$for $($j $=1$; j $<6$; j $+=2)$

$$y $+=$ x$[$i$\%3][$j$\%3]$;

cout $<<$ y $<<$ endl;