#pragma GCC optimize ("Ofast")
#include<bits/stdc++.h>
using namespace std;
#define MD (1000000007U)
void *wmem;
char memarr[96000000];
template<class T> inline void walloc1d(T **arr, int x, void **mem = &wmem){
  static int skip[16] = {0, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
  (*mem) = (void*)( ((char*)(*mem)) + skip[((unsigned long long)(*mem)) & 15] );
  (*arr)=(T*)(*mem);
  (*mem)=((*arr)+x);
}
inline int my_getchar_unlocked(){
  static char buf[1048576];
  static int s = 1048576;
  static int e = 1048576;
  if(s == e && e == 1048576){
    e = fread_unlocked(buf, 1, 1048576, stdin);
    s = 0;
  }
  if(s == e){
    return EOF;
  }
  return buf[s++];
}
inline void rd(int &x){
  int k;
  int m=0;
  x=0;
  for(;;){
    k = my_getchar_unlocked();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = my_getchar_unlocked();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
struct MY_WRITER{
  char buf[1048576];
  int s;
  int e;
  MY_WRITER(){
    s = 0;
    e = 1048576;
  }
  ~MY_WRITER(){
    if(s){
      fwrite_unlocked(buf, 1, s, stdout);
    }
  }
}
;
MY_WRITER MY_WRITER_VAR;
void my_putchar_unlocked(int a){
  if(MY_WRITER_VAR.s == MY_WRITER_VAR.e){
    fwrite_unlocked(MY_WRITER_VAR.buf, 1, MY_WRITER_VAR.s, stdout);
    MY_WRITER_VAR.s = 0;
  }
  MY_WRITER_VAR.buf[MY_WRITER_VAR.s++] = a;
}
inline void wt_L(char a){
  my_putchar_unlocked(a);
}
inline void wt_L(long long x){
  int s=0;
  int m=0;
  char f[20];
  if(x<0){
    m=1;
    x=-x;
  }
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  if(m){
    my_putchar_unlocked('-');
  }
  while(s--){
    my_putchar_unlocked(f[s]+'0');
  }
}
struct graph{
  int N;
  int *es;
  int **edge;
  void setDirectEdge(int N__, int M, int A[], int B[], void **mem = &wmem){
    int i;
    N = N__;
    walloc1d(&es, N, mem);
    walloc1d(&edge, N, mem);
    walloc1d(&edge[0], M, mem);
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      es[A[i]]++;
    }
    for(i=(0);i<(N);i++){
      walloc1d(&edge[i], es[i], mem);
    }
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      edge[A[i]][es[A[i]]++] = B[i];
    }
  }
  void getDist(int root, int res[], void *mem = wmem){
    int i;
    int j;
    int k;
    int*q;
    int s;
    int z;
    walloc1d(&q, N, &mem);
    for(i=(0);i<(N);i++){
      res[i]=-1;
    }
    res[root]=0;
    s=0;
    z=1;
    q[0]=root;
    while(z){
      i=q[s++];
      z--;
      for(j=(0);j<(es[i]);j++){
        k=edge[i][j];
        if(res[k]>=0){
          continue;
        }
        res[k]=res[i]+1;
        q[s+z++]=k;
      }
    }
  }
}
;
int N;
int A[1000000];
int B[1000000];
graph g;
int d[1000000];
int deg[1000000];
int main(){
  int i;
  wmem = memarr;
  long long res = 0;
  rd(N);
  {
    int Lj4PdHRW;
    for(Lj4PdHRW=(0);Lj4PdHRW<(N-1);Lj4PdHRW++){
      rd(A[Lj4PdHRW]);A[Lj4PdHRW] += (-1);
      rd(B[Lj4PdHRW]);B[Lj4PdHRW] += (-1);
    }
  }
  g.setDirectEdge(N, N-1, A, B);
  for(i=(0);i<(N-1);i++){
    deg[B[i]]++;
  }
  for(i=(0);i<(N);i++){
    if(deg[i]==0){
      break;
    }
  }
  g.getDist(i, d);
  for(i=(0);i<(N);i++){
    res += (long long) d[i] * (d[i] + 1) / 2;
  }
  wt_L(res%MD);
  wt_L('\n');
  return 0;
}
// cLay varsion 20200509-1

// --- original code ---
// int N, A[1d6], B[1d6];
// graph g;
// int d[1d6], deg[1d6];
// {
//   ll res = 0;
//   rd(N,(A--,B--)(N-1));
//   g.setDirectEdge(N, N-1, A, B);
//   rep(i,N-1) deg[B[i]]++;
//   rep(i,N) if(deg[i]==0) break;
//   g.getDist(i, d);
//   rep(i,N) res += (ll) d[i] * (d[i] + 1) / 2;
//   wt(res%MD);
// }