Runtime Error
/in/foo.cc: In function 'int main()':
/in/foo.cc:21:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if(a[j].size()<=k)
~~~~~~~~~~~^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:21:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
if(a[j].size()<=k)
~~~~~~~~~~~^~~
