Help me in Explain last line print((count2-count1)//2-1)

help
,
1

My issue

Explain last line print((count2-count1)//2-1) please

T=int(input())
for _ in range(T):
i=int(input())
chef=input()
other=input()
count1=0
count2=0
count=0
for j in range(i):
if(chef[j]==other[j]):
count+=1
elif((chef[j]==“R” and other[j]==“S”) or (chef[j]==“P” and other[j]==“R”) or (chef[j]==“S” and other[j]==“P”)):
count1+=1
else:
count2+=1
if(count2<count1):
print(0)
elif(count1==count2):
print(1)
else:
print((count2-count1)//2-1)

My code

T=int(input())
for _ in range(T):
    i=int(input())
    chef=input()
    other=input()
    count1=0
    count2=0
    count=0
    for j in range(i):
        if(chef[j]==other[j]):
            count+=1
        elif((chef[j]=="R" and other[j]=="S") or (chef[j]=="P" and other[j]=="R") or (chef[j]=="S" and other[j]=="P")):
            count1+=1
        else:
            count2+=1
    if(count2<count1):
        print(0)
    elif(count1==count2):
        print(1)
    else:
        print((count2-count1)//2-1)

Problem Link: PASCRO Problem - CodeChef

2

@veerendra22
for test case
1
3
PSP
SRP
your output is
0
but the correct output will be 2.