01: sample test (n=5)
02: minimal test (n=1)
    coinciding segments (answer=0):
03: n=2
04: n=13
05: n=200 (maximal test)
06: n=200 (maximal size of input)
    ladder (each k sequential segments share a segment):
07: n=170 k=17
08: n=200 k=2
09: n=186 k=120
    enclosed segments [0 [1 [2 ... 2] 1] 0]:
10: n=15
11: n=200
    all cases of three segments relations
12: scale 1
13: scale 2
    no two segments intersect
14: n=3
15: n=200
    g pairwise non-intersecting groups of segments
    having a common segment (just a knapsack):
16: n=13 g=3
17: n=200 g=50
18: n=200 g=50 (perfect solution exists)
    random test
19: n=173
20: n=199
21: n=200
    union of ladders (k1, k2, ...):
22: n1=15 k1=3, n2=100 k2=2
23: n1=15 k1=3, n2=50 k2=2, n3=100 k3=30
24: n1=5 k1=3, n2=100 k2=20
25: n1=100 k1=2, n2=10 k2=3
26: n1=100 k1=2, n2=50 k2=4, n3=25 k3=8, n4=12 k4=12
27: starts form a parabola sqrt(x); ends --- sqrt(2x)
