In each 7x7 grid, diamonds have been hidden in 10 of the 49 squares.   Your task is to determine the positions of the diamonds.   The numbers in the diagram provide clues: A number in a square indicates how many diamonds lie next to the square - in other words, how many adjacent squares (including diagonally adjacent squares) contain diamonds.   No square with a number in it contains a diamond, and a diamond may appear in a square with no numbers adjacent to it.