/in/foo.cc: In function 'int main()':
/in/foo.cc:40:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17' [-Wc++17-extensions]
   40 |         for(auto [to,len]:G[i])
      |                  ^
/in/foo.cc:55:26: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17' [-Wc++17-extensions]
   55 |                     auto [d,now]=Q.top();
      |                          ^
/in/foo.cc:60:30: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17' [-Wc++17-extensions]
   60 |                     for(auto [to,len]:G[now])
      |                              ^
/in/foo.cc:73:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17' [-Wc++17-extensions]
   73 |         for(auto [to,len]:G[i])
      |                  ^
/in/foo.cc:38:9: warning: unused variable 'tot' [-Wunused-variable]
   38 |     int tot=0;
      |         ^~~