function f=lock(t,A)
if det(A)==0|gcd(det(A),26)~=1
    error('It is impossiable')
end
a=mod(abs(t)-64,26);
k=length(a);
if mod(k,2)~=0
    a(k+1)=a(k);
end
for i=1:length(a)/2
    b(1,i)=a(2*i-1);
    b(2,i)=a(2*i);
%end
b;
%for i=1:length(a)/2
    c(:,i)=mod(A*b(:,i),26);
end
c;
d=c(:)';
d(d==0)=26;
e=setstr(d+64)