x   = importdata('input.txt');
L   = size(x,1);
N   = 25; 
P25 = x(1:N);

%Part A:
for idx = N+1:L
   z = repmat(P25,1,N);
   T = z+z';
   T(1:N+1:N^2)=-1;
   if ~any(any(x(idx)==T))
      answerPartA = x(idx)
      break
   end
   P25 = x(idx+1-N:idx);
end

%Part B:
for i=1:L
   for j=i+1:L
       if sum(x(i:j))<answerPartA
           continue
       elseif sum(x(i:j))==answerPartA
           answerPartB = min(x(i:j))+max(x(i:j))
       else
           break
       end
   end
end