program p_1;

var a,b:array[1..1000]of longint;

c,d,i,j,k,m,n,x,y,z:integer;

begin

readln(k);

for i:=1 to k do read(a[i]);

c:=1;j:=a[1];x:=a[2];y:=k+1;z:=2;

while z>1 do

begin

z:=0;j:=20001;x:=j;

for i:=1 to y do

if (a[i]>0)and(a[i]0)and(a[i]