Lasiommata petrovitana (Fabricius, 1787)

I think it's Lasiommata petrovitana. The photo is a little blurry, but you can still see a blurry wavy pattern on the wings.

After Yulia clarified the biotope in which the butterfly was photographed, we can definitely say that it is petrovitana.
Proposed new signature:

St. Petersburg velvet
Lasiommata petrovitana (Fabricius, 1787)

The butterfly got its name because in the vicinity of St. Petersburg - its typical location.
It flies in May and June. The caterpillars feed on cereals (Poa sp., Calamagrostis epigeios, Festuca ovina, Dactylus glomerata).
Lasiommata maera differs from the closely related species in the presence of an indistinct wavy pattern on the wings. The ecological difference is also significant. L. maera prefers dense mixed forests with rich undergrowth, where it is found on the edges and redlands. L. petropolitana is a typical inhabitant of non-watered, pine - covered areas of peat bogs, as well as dry pine forests on poor soils.
The butterfly's range is boreal-montane (taiga zone from Fennoscandia to Primorye, to the south-locally in peat bogs and in the mountains of Southern Europe and Turkey). This distribution is typical of Ice Age relics.