var
a:array [1..70] of integer;
b:array [1..35] of integer;
i,minsum:integer;
begin
minsum:=100000;
for i:=1 to 70 do
begin
read(a[i]);
if a[i] > 0 then
b[i]:=a[i]+a[i+1]
else
a[i]:=1
end;
for i:=1 to 35 do
begin
if (b[i] < minsum) and (b[i] mod 2 = 0) then 
minsum:=b[i];
end;
writeln(minsum);
end.