#include <boost/multiprecision/cpp_int.hpp>
#include <iostream>
 
int main()
{
   using namespace boost::multiprecision;
 
   int128_t v = 1;
 
   // Do some fixed precision arithmetic:
   for(unsigned i = 1; i <= 20; ++i)
      v *= i;
 
   std::cout << v << std::endl; // prints 20!
 
   // Repeat at arbitrary precision:
   cpp_int u = 1;
   for(unsigned i = 1; i <= 100; ++i)
      u *= i;
 
   std::cout << u << std::endl; // prints 100!
 
   return 0;
}

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