Wrong Answer
/in/foo.cc: In function 'int main()':
/in/foo.cc:113:19: warning: 'head' may be used uninitialized in this function [-Wmaybe-uninitialized]
a[i].rclas=i-head+1;
~^~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:113:19: warning: 'head' may be used uninitialized in this function [-Wmaybe-uninitialized]
a[i].rclas=i-head+1;
~^~~~~
