GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
1#include "tools.h" 2 3#define RANDOM_PRIME 19853 4#define step 12345 5int random_own() 6{ 7 8 static int erg; 9 10 erg += step; 11 erg = erg % RANDOM_PRIME; 12 13 return erg; 14 15} 16 17