/in/foo.cc: In function 'void tree_dp(long long int, long long int)':
/in/foo.cc:53:42: warning: iteration 3 invokes undefined behavior [-Waggressive-loop-optimizations]
             dp[from][(j+val)%7]+=dp[to][j];
                                  ~~~~~~~~^
/in/foo.cc:11:42: note: within this loop
 #define rep(i,s,e) for(register int i=s;i<=e;++i)
                                           
/in/foo.cc:52:13:
         rep(j,0,6)
             ~~~~~                         
/in/foo.cc:52:9: note: in expansion of macro 'rep'
         rep(j,0,6)
         ^~~
/in/foo.cc:51:26: warning: iteration 3 invokes undefined behavior [-Waggressive-loop-optimizations]
             ans+=dp[to][j]*dp[from][((-j-val)%7+7)%7]*6;
                  ~~~~~~~~^
/in/foo.cc:11:42: note: within this loop
 #define rep(i,s,e) for(register int i=s;i<=e;++i)
                                           
/in/foo.cc:50:13:
         rep(j,0,6)
             ~~~~~                         
/in/foo.cc:50:9: note: in expansion of macro 'rep'
         rep(j,0,6)
         ^~~