#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define syosu(x) fixed< P; typedef pair pdd; typedef pair pll; typedef vector vi; typedef vector vvi; typedef vector vd; typedef vector vvd; typedef vector vl; typedef vector vvl; typedef vector vc; typedef vector vvc; typedef vector vs; typedef vector vb; typedef vector vvb; typedef vector

vp; typedef vector vvp; typedef vector vpll; typedef pair pip; typedef vector vip; const int inf=1<<30; const ll INF=1ll<<57; const double pi=acos(-1); const double eps=1e-6; const ll mod=1e9+7; const int dx[4]={0,1,0,-1},dy[4]={1,0,-1,-0}; const int DX[8]={-1,-1,-1,0,1,1,1,0},DY[8]={1,0,-1,-1,-1,0,1,1}; int n; int main(){ cin>>n; ll res=0; for(int i=0;i>c>>d; c%=mod; d%=mod; (res+=(c/2+1)*d)%=mod; } cout<