ll f(ll a,ll b){return~-gcd(a,b)?0:--a*--b;}ll u,v,z;{ll@n;if(n<4){ll@a,@b;z=f(a,b);if(n>2){ll@c,x=f(f(b,c),a),y=f(f(a,c),b);z=f(z,c);z=z>x|z>y?v=1,x<y?u=1,x:y:z;}}wt(z);rep(i,n)wt(u+1,v+2),u=v=0;}