Polygon area

n = int(input())
vertices = []
for _ in range(n):
    x1, y1 = [int(x) for x in input().split()]
    vertices.append([x1, y1])

area = 0.0
for i in range(n):
    j = (i+1)%n
    area += vertices[i][0]*vertices[j][1] - vertices[i][1]*vertices[j][0]

print(abs(int(area)))

Test 1

Verdict: ACCEPTED

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: ACCEPTED