a problem in my program in pascal


I want to write the pattern " for i:=1 to a[i] do" n times (n is
variable), that is,


for b[1]:=1 to a[1] do
for b[2]:=1 to a[2] do
for b[3]:=1 to a[3] do
for b[4]:=1 to a[4] do
.........
..........
.........
for b[n]:=1 to a[n] do
something here.


in this writing n is a variable. therefore I can not write what i want.
can you say how can i write the above structure using "repeat-until" or
"while" patterns?

thanks in advance.

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