You should specify what language you're using in these types of questions. Here's an example in C++, which is fairly easy to understand, so you should be able to transfer the concept to another language to problem.
int x = 2, y = 1, z = 3, min;
if (x < y && x < z)
min = x;
else if (y < x && y < z)
min = y;
else if (z < x && z < y)
min = z;
else
std::cout << "There is no minimum";
