#include <stdio.h>

#define M1 259200
#define IA1 7141
#define IC1 54773
#define RM1 (1.0/M1)
#define M2 134456
#define IA2 8121
#define IC2 28411
#define RM2 (1.0/M2)
#define M3 243000
#define IA3 4561
#define IC3 51349

double ran1(idum)
     int *idum;
{
  static long ix1,ix2,ix3;
  static double r[98];
  double temp;
  static int iff=0;
  int j;
  void nrerror();
  
  if (*idum < 0 || iff == 0) {
    iff=1;
    ix1=(IC1-(*idum)) % M1;
    ix1=(IA1*ix1+IC1) % M1;
    ix2=ix1 % M2;
    ix1=(IA1*ix1+IC1) % M1;
    ix3=ix1 % M3;
    for (j=1;j<=97;j++) {
      ix1=(IA1*ix1+IC1) % M1;
      ix2=(IA2*ix2+IC2) % M2;
      r[j]=(ix1+ix2*RM2)*RM1;
    }
    *idum=1;
  }
  ix1=(IA1*ix1+IC1) % M1;
  ix2=(IA2*ix2+IC2) % M2;
  ix3=(IA3*ix3+IC3) % M3;
  j=1 + ((97*ix3)/M3);
  if (j > 97 || j < 1) {
    printf("RAN1: Error RNG stack is broken.");
    exit(1);
  }
  temp=r[j];
  r[j]=(ix1+ix2*RM2)*RM1;
  return temp;
}

#undef M1
#undef IA1
#undef IC1
#undef RM1
#undef M2
#undef IA2
#undef IC2
#undef RM2
#undef M3
#undef IA3
#undef IC3