upgrade to ubuntu 12.04 breaks compiling

[A. Grigoryants]

the code was compiled OK on Ubuntu 10.04 64-bit
when upgrading to 12.04 64-bit the error occurs :


  In function `std::basic_istream<char, std::char_traits<char> >& 
operator>><__mpz_struct [1]>(std::basic_istream<char, 
std::char_traits<char> >&, __gmp_expr<__mpz_struct [1], __mpz_struct 
[1]>&)':
/usr/include/gmpxx.h:2100: undefined reference to 
`operator>>(std::basic_istream<char, std::char_traits<char> >&, 
__mpz_struct*)'

any direction to search, please .......