mod = 1000000007
def qmod(a,n):
	res = 1
	while(n):
		if n % 2 == 1:
			res = res * n % mod
		a = a * a % mod
		n >>= 1
	return res % mod
	
ans = 1
n = input()
n = int(n)

for i in range(0,n):
	a = input()
	b = a.split(' ')
	#print(b)
	ans = ans * (int(b[0]) + int(b[1]))
#ans = ans*qmod(2,n) % mod
print(ans)