19
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//Pascal
function easy(a:longint):boolean;
var
i:integer;
begin
easy:=true;
if a<2 then <br> easy:=false else
for i:=1 to a div 2 do
if ((a mod i)=0) and (i<>1) then
easy:=false;
end;
var
i, k: integer;
num: array [0..100] of integer;
begin
for i:=0 to 99 do
num[i+1] := i+1;
k:=0;
i:=1;
while k<7 do <br>begin
if easy(num[i])=true then
k:=k+1;
i:=i+2;
end;
write(num[i-2]);
end.