import statistics as st 
def interQuartile(values, freqs):
s = []
for i in range(len(freqs)):
for j in range(freqs[i]):
s.append(values[i]) 
s.sort() 
m = int(len(s)/2) 
a = st.median(s[:m])
b = st.median(s[m+1:])

return print(float(b-a))