/in/foo.cc: In function 'long long int __BigInt_b::convert_i(const std::vector<int>&)':
/in/foo.cc:35:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < a.size(); ++ i)
                     ~~^~~~~~~~~~
/in/foo.cc:37:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'std::vector<int> __BigInt_b::addi(const std::vector<int>&, const std::vector<int>&)':
/in/foo.cc:58:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < b.size() || c[i] >= MOD; ++ i)
                     ~~^~~~~~~~~~
/in/foo.cc:60:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (i < b.size()) c[i] += b[i];
             ~~^~~~~~~~~~
/in/foo.cc: In function 'std::vector<int> __BigInt_b::subt(const std::vector<int>&, const std::vector<int>&)':
/in/foo.cc:70:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < a.size() && (i < b.size() || c[i] < 0); ++ i)
                     ~~^~~~~~~~~~
/in/foo.cc:70:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < a.size() && (i < b.size() || c[i] < 0); ++ i)
                                      ~~^~~~~~~~~~
/in/foo.cc:72:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (i < b.size()) c[i] -= b[i];
             ~~^~~~~~~~~~
/in/foo.cc: In function 'std::vector<int> __BigInt_b::mult(const std::vector<int>&, const std::vector<int>&)':
/in/foo.cc:84:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < a.size(); ++ i)
                     ~~^~~~~~~~~~
/in/foo.cc:86:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int j = 0; j < b.size(); ++ j)
                         ~~^~~~~~~~~~
/in/foo.cc: In function 'void __BigInt_b::trial_division(const std::vector<int>&, const std::vector<int>&, std::vector<int>&, std::vector<int>&)':
/in/foo.cc:143:5: warning: left operand of comma operator has no effect [-Wunused-value]
     c, d = a; c.clear(); c.resize(a.size() - b.size() + 1);
     ^
/in/foo.cc:130:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int j = 0; j < b.size(); ++ j)\
                     ~~^~~~~~~~~~
/in/foo.cc:148:13: note: in expansion of macro '__trial_division_subt'
             __trial_division_subt();
             ^~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:130:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int j = 0; j < b.size(); ++ j)\
                     ~~^~~~~~~~~~
/in/foo.cc:155:16: note: in expansion of macro '__trial_division_subt'
         if (p) __trial_division_subt();
                ^~~~~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'int lowbit(BigInt)':
/in/foo.cc:289:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < s.size(); ++ i)
                     ~~^~~~~~~~~~
/in/foo.cc: At global scope:
/in/foo.cc:472:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^
/in/foo.cc: In function 'int lowbit(BigInt)':
/in/foo.cc:291:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^