Help me in solving SESO10 problem

help
, ,
1

My issue

why is this code faling on a hidden test case when the logic is correct

My code

n=int(input())

pairs=[]
for _ in range(n):
    a,b=map(int,input().split())
    pairs.append((a,b))
    

left,right=map(int,input().split())

fvp=False

for a,b in pairs:
    sumpair=a+b
    propair=a*b
    
    if left<=sumpair<=right and left<=propair<=right:
        print(f"({a},{b})")
        fvp=True

if not fvp:
    print("No pairs found")

Learning course: Data structures & Algorithms lab
Problem Link: https://www.codechef.com/learn/course/muj-aiml-dsa-c/MUJADSAC11/problems/SESO10