Vodka
Vodka is a key element of Slavic tradition in some countries of Eastern Europe (especially Poland, Belarus, Ukraine and Russia). It has also spread to become a part of national culture in Baltic countries like Lithuania and Nordic countries like Sweden. It's traditional in Russia and other Slavic countries (as well as some Roma communities in Eastern Europe) to put a glass of vodka with a slice of bread (usually black bread) on top on graves or near photos of the deceased in their memory. This is similar to what people in Western countries do with flowers.