program rishon;
	var
		v,x,y,j,a,b,rishoni,a_rishoni,b_rishoni,i,hefresh,hefresh_r:integer;
	begin
		a:=0;
		b:=0;
		hefresh_r:=0;
		rishoni:=0;
		a_rishoni:=0;
		b_rishoni:=0;
		hefresh:=0;
		for i:=10 to 99 do
                    begin
				for j:=2 to i div 2 do
					if i mod j=0 then
						rishoni:=1;
				a:=i mod 10;
				b:=i div 10;
				for x:=2 to a div 2 do
					if a mod x=0 then
						a_rishoni:=1;
				for y:=2 to b div 2 do
					if a mod y=0 then
						b_rishoni:=1;
				if a>b then
					hefresh:=a-b;
				if b>a then
					hefresh:=b-a;
				for v:=2 to hefresh div 2 do
					if hefresh mod v=0 then
						hefresh_r:=1;
				if (rishoni=0) and (a_rishoni=0) and (b_rishoni=0) and (hefresh_r=0) then
					writeln(i);
                    end;
	end.