Maestro n° 103 : Page 58 - Gr 55
r3c1 =4= r4c1 -4-2- r4c1 =2= r4c8 -2-8- r4c8 =8= r5c8 -8- r5c5 =8=1= r5c5 -1- r7c5 =1= r7c2 -1-5- r7c2 =5= r3c2 => r3c2 ≠ 4 and r3c1 ≠ 5