/in/foo.cc: In function 'std::vector<int> BigInt::read()':
/in/foo.cc:48:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < s.size(); i++) {
                     ~~^~~~~~~~~~
/in/foo.cc: In function 'void BigInt::print(std::vector<int>&)':
/in/foo.cc:58:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < A.size(); i++)
                     ~~^~~~~~~~~~
/in/foo.cc: In function 'std::vector<int> BigInt::sub(std::vector<int>, std::vector<int>)':
/in/foo.cc:119:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < A.size(); i++) {
                     ~~^~~~~~~~~~
/in/foo.cc:120:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (i < B.size()) {
             ~~^~~~~~~~~~
/in/foo.cc: In function 'std::vector<int> BigInt::mul(std::vector<int>, int)':
/in/foo.cc:141:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < A.size(); i++) {
                     ~~^~~~~~~~~~

FormatError('config file not found',)