f=@(x)exp(-x);
a=0;
b=1;
n=65;
h=1/64;
s=0;
t=0;
for i=1:65
  x(i)=a+(i-1)*h;
end

for i=1:64
  t=t+(f(x(i))+f(x(i+1)))*h/2;
end

for i=1:(n-1)/2
  s=s+(f(x(2*i-1))+4*f(x(2*i))+f(x(2*i+1)))*h/3;
end