721 B | 721 chars
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from decimal import Decimal
BLANK = " "
# inp = input
inp = lambda : sys.stdin.readline()[:-1].strip()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
n, k = mii()
l = [mii() for _ in range(k)]
d = [n, n]
for x, y in l:
if d[0] <= x or d[1] <= y:
continue
left1 = x * d[1]
left2 = d[0] * y
if left1 >= left2:
d = [x, d[1]]
else:
d = [d[0], y]
p(d[0] * d[1])
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()