/in/foo.cc: In function 'int sap(int, int, int, int, int)':
/in/foo.cc:83:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (register int i = iter[v]; i < edge[v].size(); i++) {
                                    ~~^~~~~~~~~~~~~~~~
/in/foo.cc: In instantiation of 'void BufferedInputStream::read(T&) [with T = int]':
/in/foo.cc:52:15:   required from here
/in/foo.cc:33:20: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
             x = (x + (x << 2) << 1) + (c ^ '0');
                  ~~^~~~~~~~~~
/in/foo.cc: In instantiation of 'void BufferedInputStream::read(T&) [with T = long long int]':
/in/foo.cc:58:15:   required from here
/in/foo.cc:33:20: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
/in/foo.cc: In function 'int main()':
/in/foo.cc:69:60: warning: 'h' may be used uninitialized in this function [-Wmaybe-uninitialized]
     Node(int v, int f, int index) : v(v), f(f), index(index) {}
                                                            ^
/in/foo.cc:108:36: note: 'h' was declared here
     for (register int i = 0, a, b, h; i < m; i++) {
                                    ^
/in/foo.cc:108:30: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]
     for (register int i = 0, a, b, h; i < m; i++) {
                              ^