Krylov borrowed a considerable amount of money from Vor

Krylov borrowed a large amount of money from Voronova with the obligation to return the debt in 2 months, i.e. no later than August 15, 1998. No money was returned within this period. Instead of money, Krylov issued a new receipt to Voronov, for which he pledged to pay the Voronovo sum, increased by 50%, no later than December 1, 1998.
In November 1998, Krylov was called up for active military service, which took place in the remote border garrison. After demobilization in November 2000, Krylov did not return home, settling in a seaside town, where he got a job in a shipping company.
Having learned from Krylov´s relatives his address, Voronova sent him a letter reminding him of her duty, but received no answer. On January 20, 2002, Voronova filed a lawsuit seeking the recovery of debt from Krylov. Krylov did not admit the claim, referring to the omission of the Voronovo limitation period. Voronova believed that the prescription did not expire, since, in her opinion, the time of Krylov’s service in the army should not be counted in the limitation period. In addition, Voronova submitted to the court medical documents confirming that for two months, from September 3 to November 5, 2001, she was treated in a hospital.
Who is right in this dispute? Will the solution of the problem change if Krylov responded to Voronova’s letter and promised to return the debt by some new date?