Wrong Answer
/in/foo.cc: In function 'int main()':
/in/foo.cc:18:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (long long i = 1; i < st.size(); i++) {
~~^~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:18:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (long long i = 1; i < st.size(); i++) {
~~^~~~~~~~~~~
