样例1：
4 3
1 foot = 12 inch
1 yard = 3 foot
1 meter = 100 centimeter
1 centimeter = 10 millimeter
750 millimeter to meter
42 yard to inch
10 meter to foot
样例2：
4 3
1 fortnight = 14 day
1 microcentury = 0.036525 day
1 microcentury = 1000 nanocentury
1 week = 7 day
22.2 fortnight to nanocentury
2.5 nanocentury to week
3.14 day to fortnight
样例3：
10 2
1 micrometer = 1000 nanometer
1 millimeter = 1000 micrometer
1 meter = 1000 millimeter
1 kilometer = 1000 meter
1 megameter = 1000 kilometer
1 lightsecond = 299.792458 meter
1 lightminute = 60 lightsecond
1 lighthour = 60 lightminute
1 lightday = 24 lighthour
1 lightyear = 365.25 lightday
42 nanometer to lightyear
42 lightyear to nanometer