2-1 4-3 6-5 8-7 10-9 12-11 14-13 16-15 18-17 20-19 22-21 24-23 26-25 28-27 30-29 32-31 34-33 36-35 38-37 40-39 42-41 44-43 46-45 48-47 50-49 52-51 54-53 56-55 58-57 60-59 62-61 64-63 66-65 68-67 70-69 72-71 74-73 76-75 78-77 80-79 82-81 84-83 86-85 88-87 90-89 92-91 94-93 96-95 98-97 100-99 102-101 104-103 106-105 107