| t | import math | t | import math | 
            |  |  |  |  | 
            |  | def cross_product(o, a, b): |  | def cross_product(o, a, b): | 
            |  | return (a[0] - o[0]) * (b[1] - o[1]) - (a[1] - o[1]) * (b[0] - o[0]) |  | return (a[0] - o[0]) * (b[1] - o[1]) - (a[1] - o[1]) * (b[0] - o[0]) | 
            |  |  |  |  | 
            |  | def is_convex_polygon(points): |  | def is_convex_polygon(points): | 
            |  | if len(points) < 3: |  | if len(points) < 3: | 
            |  | return False |  | return False | 
            |  | start = min(points, key=lambda p: (p[1], p[0])) |  | start = min(points, key=lambda p: (p[1], p[0])) | 
            |  | points.remove(start) |  | points.remove(start) | 
            |  | points.sort(key=lambda p: (math.atan2(p[1] - start[1], p[0] - start[ |  | points.sort(key=lambda p: (math.atan2(p[1] - start[1], p[0] - start[ | 
            |  | 0]), p[0], p[1])) |  | 0]), p[0], p[1])) | 
            |  | points.insert(0, start) |  | points.insert(0, start) | 
            |  | hull = [points[0], points[1]] |  | hull = [points[0], points[1]] | 
            |  | for i in range(2, len(points)): |  | for i in range(2, len(points)): | 
            |  | while len(hull) > 1 and cross_product(hull[-2], hull[-1], points |  | while len(hull) > 1 and cross_product(hull[-2], hull[-1], points | 
            |  | [i]) <= 0: |  | [i]) <= 0: | 
            |  | hull.pop() |  | hull.pop() | 
            |  | hull.append(points[i]) |  | hull.append(points[i]) | 
            |  | if len(hull) == len(points): |  | if len(hull) == len(points): | 
            |  | return True |  | return True | 
            |  | return False |  | return False | 
            |  |  |  |  | 
            |  | def main(): |  | def main(): | 
            |  | points = [] |  | points = [] | 
            |  | while True: |  | while True: | 
            |  | line = input().strip() |  | line = input().strip() | 
            |  | if not line: |  | if not line: | 
            |  | break |  | break | 
            |  | x, y = map(int, line.split(',')) |  | x, y = map(int, line.split(',')) | 
            |  | points.append((x, y)) |  | points.append((x, y)) | 
            |  | if is_convex_polygon(points): |  | if is_convex_polygon(points): | 
            |  | print(True) |  | print(True) | 
            |  | else: |  | else: | 
            |  | print(False) |  | print(False) | 
            |  | main() |  | main() |