Divide the 10x10 square in ten
different,
distinct rectangles so that each one has a dot at a corner.
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | | | | |
+---+---+---+---+---+---+---+---+---+---+
| | O | | | | | O | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | O | | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | O | | | | | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | | | | O |
+---+---+---+---+---+---+---+---+---+---+
| | | | O | | | O | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | | O | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | O | O | | |
+---+---+---+---+---+---+---+---+---+---+
+---+---+---+---+---+---+---+---+---+---+
| A | A | B | B | B | B | B | C | C | C |
+---+---+---+---+---+---+---+---+---+---+
| A | O | B | B | B | B | O | C | C | C |
+---+---+---+---+---+---+---+---+---+---+
| D | D | D | D | D | D | E | C | C | C |
+---+---+---+---+---+---+---+---+---+---+
| D | D | D | D | D | O | E | C | C | C |
+---+---+---+---+---+---+---+---+---+---+
| F | F | O | G | G | G | E | C | C | C |
+---+---+---+---+---+---+---+---+---+---+
| F | F | F | G | G | G | E | C | C | C |
+---+---+---+---+---+---+---+---+---+---+
| F | F | F | G | G | G | E | C | C | O |
+---+---+---+---+---+---+---+---+---+---+
| F | F | F | O | G | G | O | H | H | H |
+---+---+---+---+---+---+---+---+---+---+
| F | F | F | I | I | I | I | O | H | H |
+---+---+---+---+---+---+---+---+---+---+
| F | F | F | I | I | I | O | O | J | J |
+---+---+---+---+---+---+---+---+---+---+