OpenMP Version(N=25000, M=25000, Threads=1): t= 456.858909 ms
OpenMP Version(N=25000, M=25000, Threads=2): t= 228.760691 ms
OpenMP Version(N=25000, M=25000, Threads=5): t= 94.036951 ms
OpenMP Version(N=25000, M=25000, Threads=10): t= 49.852111 ms
OpenMP Version(N=25000, M=25000, Threads=20): t= 30.018451 ms
OpenMP Version(N=25000, M=25000, Threads=40): t= 27.299979 ms