View Compilation Error

841157_0_0_13341.cpp: In function `int main()':
841157_0_0_13341.cpp:213: error: could not convert `((void)operator>>(((std::istream&)(+operator>>(((std::istream&)(&std::cin)), ((bignum&)(&a))))), ((bignum&)(&b))), operator+(const bignum&, const bignum&)(((const bignum&)((const bignum*)(&b)))))' to `bool'