Once upon a time, there was a landowner, Gumuyi, who hired a long-term worker named Zach and promised to pay a cow every year. By the end of the year, Guyimu said to Zach, I have your salary, and you can do great things in the future. Honest Zach agreed. In a blink of an eye, 19 years passed, Zach was old and weak, and Mu Yi, the customer of the earth, wanted to dismiss him. One day, Gu Yimu called Zach and said, "You worked in my house for 19 years. Here's 19 Jin of oil. Go! " Zach listened and said, "Sir, how did your salary for a cow become a catty of oil every year?" Gu Muyi glared at him and growled, "That's because you heard wrong. Will the master still rely on you? " I kicked him out of the house without saying anything.

Zach was sitting on the side of the road with 19 Jin of oil. At this time, I happened to see two generations of love riding a little donkey. Zach quickly told Avanti about it and asked him to help calculate the salary. Afandi thought about it and said, OK, I'll go to Muyi's house with you to judge. "

Gumuyi was drinking at home when suddenly two generations of love and Zach came in. Gu Muyi was a little flustered and smiled and said, "Mr. Two generations of love have arrived. What can I do for you? " Afandi said, "Zach wants to do some small business, and he has come to lend me three taels of silver, and I will guarantee it. I wonder if the master will agree. " Listen to the gu, this just relieved, even said, "of course, Mr. Do the guarantor. Zach is an honest man, and the annual interest rate is good for this. " So, the third officer wrote IOUs on six sides. Gu was about to get the money when he was grabbed by a hand and said, "It's fair to do things, and the money I lent you was good. Then, a pound of oil a year for two generations should be good for Ben. " Gu rolled his eyes and wondered how much interest 19 kg of oil could bring him. It was a big deal. He said, "well, for the sake of two generations of Mr. Love, I will pay you the money you worked out."

So, Avanti said with an abacus: the first year's salary 1 kg, the second year's interest 1 kg, the processing fee 1 kg, * * 3 kg, the third year's 7 kg, and the fourth year's 15 kg ... After a while, the result was worked out. Finally, I begged again and again: "Mr. Ergeneration Love, please talk to Zach well, and I am willing to pay him 19 cows!" "

Zach got the salary of 19 cows, and of course he didn't borrow three taels of silver.

Excuse me, children, what is the principal and interest of the 19 account according to the algorithm of paying the principal and interest every year? I tell you, the result is 524287 Jin of oil. If you don't believe me, you might as well do the math yourself.