question: How many years was it between Jaroslaw's death and when Bishop Przeclaw of Pogorzeli swore the oath of fealty to King John the Blind?
#1 return Jaroslaw 's death 
#2 return Bishop Przeclaw of Pogorzeli swore the  oath of  fealty to King John the Blind 
#3 return year of #1 
#4 return year of #2 
#5 return the  difference of #4 and  #3