/usr/bin/gcc -DEVAL -std=gnu11 -O2 -pipe -static -s -o permutation permutation.c -lm
/usr/bin/g++ -DEVAL -std=gnu++20 -O2 -pipe -static -s -o permutation permutation.cpp
/usr/bin/g++ -DEVAL -std=gnu++17 -O2 -pipe -static -s -o permutation permutation.cpp
