Maestro n° 103 : Page 84 - Gr 81
L5C1 =4= L5C5 -4-7- L5C5 =7= L5C7 -7-1- L5C7 =1= L5C3 -1-5- L5C3 =5= L6C3 -5- L6C9 =5=4= L6C9 donc L6C13 ≠ 4