public static void solve(SudokuBoard b,int row, int col) {
		//is a solution?
		
		if(b.isFieldEmpty(row, col)) {
			for(int i = 1; i <= 9;i++) {
				if(b.placeNumber(row,col,i))
				{
					if(b.isSolved())
					{
						solutionCounter++;
						b.printBoard();
						
					} 
					else 
					{
						//solve next field
						findNextRow(b,row,col);
					}
					
					b.removeNumber(row, col);
				}
			}
			
			//all possibilities tried, backtrack
			
		} else {
			findNextRow(b,row,col);
		}
	}