problem

can somebody tell me what is wrong with this? On my computer, solution is correct.
code:
program euklid;
var s,s1:real;
n,k,i,j,l,m:integer;
a:array[1..1000,1..50] of real;
procedure rastojanje(i:longint);
begin
j:=0;
for j:=1 to k do s:=s+sqr(a[i,j]-a[i+1,j]);
s:=sqrt(s);
end;
begin
readln(n,k);
for i:=1 to n do
for j:=1 to k do read(a[i,j]);
for l:=1 to n-1 do
for m:=l+1 to n do
if (l=1)and (m=2) then
begin
rastojanje(l);
s1:=s;
end else
begin
rastojanje(l);
if s<s1 then s1:=s;
end;
writeln(s1:0:5);
end.