I am using Maple 15 and when i use blew code , my system freeze!

n:=readstat("Input n:");
A:=matrix(n,n,0);
for i from 1 to n do
for j from 1 to n do
A[i,j]:=readstat("value = ");
od;
od;

where i have mistake?! is there any way to get an arbitrary Matrix with double for Loop? please help me!