bn,bs=0,0 #count of boys,Sum of grades of boys
gn,gs=0,0 #Count of girls, Sum of grades of girls
while(1):
    grades=input("Enter grades = ") #Enter grades as 10b where 10 is grade and "b"->boys "g"->girls or any other character to quit.
    if('b' in grades):
        bs+=int(grades.replace('b',''))
        bn+=1
    else:
        if('g' in grades):
            gs+=int(grades.replace('g',''))
            gn+=1
        else:
            if(bn!=0): #Divide by zero error
                print("Average of boys = "+ str(bs/bn))
            if(gn!=0):
                print("Average of girls = "+ str(gs/gn))
            break