format long;

nmax = 100;
a = zeros(1,nmax);
b = zeros(1,nmax);

  n = 77, a(1) = 1; a(2) = 2;
% n = 78, a(1) = 1; a(2) = 2;
% n = 75, a(1) = 1; a(2) = 1.5;
% n = 76, a(1) = 1; a(2) = 1.5;
% n = 30, a(1) = 1; a(2) = 1.1;
% n = 40, a(1) = 1; a(2) = 1.1;
% n = 50, a(1) = 1; a(2) = 1.1;

for i = 3:n
  a(i) = a(i-1)+a(i-2);
end

b(n) = a(n);
b(n-1) = a(n-1);
for i = n-2:-1:1
  b(i) = b(i+2)-b(i+1);
end

a1 = a(1)
a2 = a(2)
a2_minus_a1 = a(2)-a(1)
b2_minus_b1 = b(2)-b(1)