public static int findDepth( String s )
		{
		    int countLeft = 0;
		    int countLeftTotal = 0;
		    int countZero = 0;
		    int depth = -1; // countLeft - 1
		    for( int i = 0; i < s.length(); i++)
		    {
		        char a = s.charAt( i );
		        switch( a ){
		        case '0':	countZero++; break;
		        case '(':	{ 	countLeft++; countLeftTotal++; }; break;
		        case ')':	{ if( depth < countLeft - 1 )
		        				depth = countLeft - 1;
		        				countLeft = 1;
		        	};break;
		        default: return -1;
		        }
		       /* if( a == '(' )
		            countLeft++;
		        else if( a == ')' && depth < ( countLeft - 1 ) )
		        {
		            depth = countLeft - 1;
		            countLeft = 1;
		        }
		        else if( a != '0' )
		        	return -1;*/
		    }
		    if( countZero == countLeftTotal + 1 )
		    	return depth;
		    else 
		    	return -1;
		}