here is the dateset:
df1 = [{'student': 'jerry', 'chinese': 102, 'math': 123, 'englisth': 99, }, {'student': 'NAME_1', 'chinese': 110, 'math': 120, 'englisth': 130}, {'student': 'lily', 'chinese': 100, 'math': 120, 'englisth': 130, }]
df2 = [{'student': 'jerry', 'gender': 'boy'}, {'student': 'NAME_1', 'gender': 'boy'}, {'student': 'lily', 'gender': 'girl'},]

Please produce the Python command to reach user's request, the plan is:
1.merge two dataset on 'student';
2. select data which gender is 'boy';
3. calculate the sum of chinese and math;
4. rank it from high to low;
5. return json as {'result': ''}