How does the grace period on a credit card work?

1. You make purchases over the course of three months
2. Each month, you make a payment equal to 3% of your debt — the bank will calculate this amount automatically. The minimum payment is 300 rubles, and it must be paid by the last business day of the following month
   
3. By the last business day of the fourth month, you repay the entire remaining debt amount without interest
   

If you are unable to pay the remaining debt amount and make the minimum payment, the grace period will end. Interest will accrue only from the fifth month.