error C2065: 'LONG_LONG_MAX' : undeclared identifier

How to resolve this error? Here is the relevant code:

synth.cpp

     #include "synth.h"
     #include "ac1.h"
     #include <string>
     #include <vector>
     #include <climits>
     #include <cstdlib>
     #include <ctime>
     #include <cmath>
     #include <list>
     #include <map>
     #include <iomanip> using namespace std;
     #include "cmdline.h"
             .
             .
             . 
coeff_t BEST_BENEFIT    = COEFF_MAX;

synth.h

#ifndef SYNTH_H
#define SYNTH_H

#include "chains.h"

chains.h

#ifndef __CHAINS_H__
#define __CHAINS_H__

#include <set>
#include <vector>
#include <map>
#include <iostream>
#include <cassert>
#include <climits>
#define myassert(cond) if(!(cond)) myabort(); else;
void    myabort();

#ifdef __CYGWIN32__
#define ASSERT assert
#else
#define ASSERT assert
#endif

using namespace std;

#define COEFF_FMT "%lld"
#define COEFF_MAX LONG_LONG_MAX
class adder;

typedef int                    cost_t;
typedef long long              coeff_t;

Thanks in advance.

P.S. What is long long? is it 128 bit integer or something else ? This is not my code I got it form the net (opensource GPL license)