 Pupils sit <unk> together without necessary materials , and often without skilled teaching staff . Moreover , the Polish schools are closed during at least five months out of the ten months of the school year due to lack of coal or other fuel . Of twenty @-@ thirty <unk> school buildings which Kraków had before 1939 , today the worst two buildings are used ... Every day , pupils have to study in several shifts . Under such circumstances , the school day , which normally lasts five hours , is reduced to one hour . 
