public String get(int num){
		if(num >= bufferlo && num <= bufferhi)
			return bufferstr;
		for(int i = 0; i < dict.size(); i++){
			Object[] pair = dict.elementAt(i);
			if(pair.length == 3){
				int lo = (Integer)pair[0];
				int hi = (Integer)pair[1];
				if(num >= lo && num <= hi){
					bufferlo = lo; bufferhi = hi; bufferstr = (String)pair[2];
					return (String)pair[2];
				}
			}else if(pair.length == 2){
				int key = (Integer)pair[0];
				if(num == key){
					bufferlo = key; bufferhi = key; bufferstr = (String)pair[1];
					return (String)pair[1];
				}
			}
		}
		return null;
	}