function A = string2pairs(s)
l = length(s);
if mod(l,2)==1
    s(l+1)=' ';
    l = l+1;
end
for k=1:l/2
    A(1,k)=char2num(s(2*k-1));
    A(2,k)=char2num(s(2*k));
end
    