/in/foo.cc: In function 'int main()':
/in/foo.cc:118:9: warning: unused variable 'u' [-Wunused-variable]
  int T, u, v, i, j; T=1;
         ^
/in/foo.cc:118:12: warning: unused variable 'v' [-Wunused-variable]
  int T, u, v, i, j; T=1;
            ^
/in/foo.cc: In function 'int sap(int, int, int)':
/in/foo.cc:74:27: warning: 'inser' may be used uninitialized in this function [-Wmaybe-uninitialized]
             u = edge[S[top]^1].to;
                      ~~~~~^