Wrong Answer
/in/foo.cc: In function 'int main()':
/in/foo.cc:24:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<a[b].size();i++){
~^~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:24:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<a[b].size();i++){
~^~~~~~~~~~~~
