With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: British Columbia's economic mainstay is logging, farming, and mining.
text_B: Colourful lakelets -LRB- Polish `` Kolorowe Jeziorka '' -RRB- is the name of three -LRB- sometimes four -RRB- artificial ponds formed in place of former mines at the slope of Wielka Kopa mountain -LRB- 871 m -RRB- in Rudawy Janowickie , range in Sudetes Mountains , Poland .. Rudawy Janowickie. Rudawy Janowickie. Sudetes. Sudetes. Poland. Poland. The biggest one and the eldest -LRB- 1785 -RRB- was named Hoffnung and now became the Purple lakelet .. Names of the other mines were  : Neues Gluck -LRB- 1793 , presently Azure Lakelet -RRB- , and Gustav Grube -LRB- 1796 ; the Green Lakelet -RRB- .. These places were mined -LRB- from 1785 to 1925 -RRB- for pyrite .. pyrite. pyrite. The lakelets have various surface elevation .. The Purple lakelet -LRB- 560 m -RRB- owes its colour to chemical composition of its banks and bottom which are abundant with iron compounds , mainly pyrite .. pyrite. pyrite. chemical composition. chemical composition. iron compounds. iron compounds. The pond is filled with water solution of sulphuric acid -LRB- pH = 3 -RRB- .. pond. pond. sulphuric acid. sulphuric acid. It is highly recommended to avoid any contact with the water for it might be dangerous .. Below Purple Lakelet there is a smaller hollow which is at times filled with waters falling from the pond above -- it is called Yellow Lakelet .. pond. pond. The colour of Azure Lakelet -LRB- 635 m ; also called  : Blue or Emerald -RRB- water is connected with the presence of copper ions .. copper. copper. Its water , besides its colour , is clean , thus during hot summer days there can be seen people bathing in it ; water is usually quite cold here , though .. summer. summer. Green Lakelet -LRB- 730 m ; also called Black Pond -RRB- , same as Azure Lakelet owes its colour to copper compounds .. copper. copper. Depending on rainfall , it temporarily disappears .. rainfall. rainfall
not_related.