Polygon area

n = int(input())
l = []
for _ in range(n):
    l.append(tuple(map(float, input().split())))
area = 0.0
for i in range(n):
    x1, y1 = l[i]
    x2, y2 = l[(i + 1) % n]
    area += x1 * y2 - x2 * y1
area = abs(area)
print(int(area))

Test 1

Verdict: ACCEPTED

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: ACCEPTED