// TODO: find more triplets for different n

sclass TripletLSFR {
  // params
  int n;
  int start = 1;
  int a, b, c; // the triplet
  
  // changing variables
  int step, value;
  
  // tap bit mask for different n's (2 through 24)
  static final int[] tapTable = {
    0x3, 0x3, 0x3, 0x5,
    0x3, 0x3, 0x2d, 0x11,
    0x9, 0x5, 0x107, 0x27,
    0x1007, 0x3, 0x100b, 0x9,
    0x81, 0x27, 0x9, 0x5,
    0x3, 0x21, 0x87
  };
  
  *(int *n, int *a, int *b, int *c) {
    value = start;
  }
  
  int cycleLength() { ret (1 << n)-1; }
  
  int next() {
    int mask = ((1 << n)-1);
    step = (step+1) & mask;
    
    int x = value;
    x ^= x << a;
    x ^= x >> b;
    x ^= x << c;
    ret value = x & mask;
  }
}