#include <bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:36777216")
#pragma GCC optimize("O2")
template <class T>
inline void RD(T &);
template <class T>
inline void OT(const T &);
inline int RD() {
  int x;
  RD(x);
  return x;
}
template <class T>
inline T &_RD(T &x) {
  RD(x);
  return x;
}
inline void RC(char &c) { scanf(" %c", &c); }
inline void RS(char *s) { scanf("%s", s); }
template <class T0, class T1>
inline void RD(T0 &x0, T1 &x1) {
  RD(x0), RD(x1);
}
template <class T0, class T1, class T2>
inline void RD(T0 &x0, T1 &x1, T2 &x2) {
  RD(x0), RD(x1), RD(x2);
}
template <class T0, class T1, class T2, class T3>
inline void RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3) {
  RD(x0), RD(x1), RD(x2), RD(x3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4) {
  RD(x0), RD(x1), RD(x2), RD(x3), RD(x4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5) {
  RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5, T6 &x6) {
  RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5), RD(x6);
}
template <class T0, class T1>
inline void OT(T0 &x0, T1 &x1) {
  OT(x0), OT(x1);
}
template <class T0, class T1, class T2>
inline void OT(T0 &x0, T1 &x1, T2 &x2) {
  OT(x0), OT(x1), OT(x2);
}
template <class T0, class T1, class T2, class T3>
inline void OT(T0 &x0, T1 &x1, T2 &x2, T3 &x3) {
  OT(x0), OT(x1), OT(x2), OT(x3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void OT(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4) {
  OT(x0), OT(x1), OT(x2), OT(x3), OT(x4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void OT(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5) {
  OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void OT(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5, T6 &x6) {
  OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5), OT(x6);
}
template <class T>
inline void RST(T &A) {
  memset(A, 0, sizeof(A));
}
template <class T0, class T1>
inline void RST(T0 &A0, T1 &A1) {
  RST(A0), RST(A1);
}
template <class T0, class T1, class T2>
inline void RST(T0 &A0, T1 &A1, T2 &A2) {
  RST(A0), RST(A1), RST(A2);
}
template <class T0, class T1, class T2, class T3>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3) {
  RST(A0), RST(A1), RST(A2), RST(A3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4) {
  RST(A0), RST(A1), RST(A2), RST(A3), RST(A4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5) {
  RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6) {
  RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5), RST(A6);
}
template <class T>
inline void CLR(T &A) {
  A.clear();
}
template <class T0, class T1>
inline void CLR(T0 &A0, T1 &A1) {
  CLR(A0), CLR(A1);
}
template <class T0, class T1, class T2>
inline void CLR(T0 &A0, T1 &A1, T2 &A2) {
  CLR(A0), CLR(A1), CLR(A2);
}
template <class T0, class T1, class T2, class T3>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6) {
  CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5), CLR(A6);
}
template <class T>
inline void CLR(T &A, int n) {
  for (int i = 0; i < int(n); ++i) CLR(A[i]);
}
template <class T>
inline void FLC(T &A, int x) {
  memset(A, x, sizeof(A));
}
template <class T0, class T1>
inline void FLC(T0 &A0, T1 &A1, int x) {
  FLC(A0, x), FLC(A1, x);
}
template <class T0, class T1, class T2>
inline void FLC(T0 &A0, T1 &A1, T2 &A2) {
  FLC(A0), FLC(A1), FLC(A2);
}
template <class T0, class T1, class T2, class T3>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3) {
  FLC(A0), FLC(A1), FLC(A2), FLC(A3);
}
template <class T0, class T1, class T2, class T3, class T4>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4) {
  FLC(A0), FLC(A1), FLC(A2), FLC(A3), FLC(A4);
}
template <class T0, class T1, class T2, class T3, class T4, class T5>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5) {
  FLC(A0), FLC(A1), FLC(A2), FLC(A3), FLC(A4), FLC(A5);
}
template <class T0, class T1, class T2, class T3, class T4, class T5, class T6>
inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6) {
  FLC(A0), FLC(A1), FLC(A2), FLC(A3), FLC(A4), FLC(A5), FLC(A6);
}
template <class T>
inline void SRT(T &A) {
  sort(A.begin(), A.end());
}
template <class T, class C>
inline void SRT(T &A, C B) {
  sort(A.begin(), A.end(), B);
}
const int MOD = 1000000007;
const int INF = 0x7fffffff;
const double PI = acos(-1.0);
const double EPS = 1e-6;
const double OO = 1e15;
template <class T>
inline void checkMin(T &a, const T b) {
  if (b < a) a = b;
}
template <class T>
inline void checkMax(T &a, const T b) {
  if (b > a) a = b;
}
template <class T, class C>
inline void checkMin(T &a, const T b, C c) {
  if (c(b, a)) a = b;
}
template <class T, class C>
inline void checkMax(T &a, const T b, C c) {
  if (c(a, b)) a = b;
}
template <class T>
inline T min(T a, T b, T c) {
  return min(min(a, b), c);
}
template <class T>
inline T max(T a, T b, T c) {
  return max(max(a, b), c);
}
template <class T>
inline T sqr(T a) {
  return a * a;
}
template <class T>
inline T cub(T a) {
  return a * a * a;
}
int Ceil(int x, int y) { return (x - 1) / y + 1; }
inline bool _1(int x, int i) { return x & 1 << i; }
inline int _1(int i) { return 1 << i; }
inline int _U(int i) { return _1(i) - 1; };
inline int count_bits(int x) {
  x = (x & 0x55555555) + ((x & 0xaaaaaaaa) >> 1);
  x = (x & 0x33333333) + ((x & 0xcccccccc) >> 2);
  x = (x & 0x0f0f0f0f) + ((x & 0xf0f0f0f0) >> 4);
  x = (x & 0x00ff00ff) + ((x & 0xff00ff00) >> 8);
  x = (x & 0x0000ffff) + ((x & 0xffff0000) >> 16);
  return x;
}
template <class T>
inline T low_bit(T x) {
  return x & -x;
}
template <class T>
inline T high_bit(T x) {
  T p = low_bit(x);
  while (p != x) x -= p, p = low_bit(x);
  return p;
}
inline void INC(int &a, int b) {
  a += b;
  if (a >= MOD) a -= MOD;
}
inline int sum(int a, int b) {
  a += b;
  if (a >= MOD) a -= MOD;
  return a;
}
inline void DEC(int &a, int b) {
  a -= b;
  if (a < 0) a += MOD;
}
inline int dff(int a, int b) {
  a -= b;
  if (a < 0) a += MOD;
  return a;
}
inline void MUL(int &a, int b) { a = (long long)a * b % MOD; }
inline int pdt(int a, int b) { return (long long)a * b % MOD; }
template <class T>
inline void RD(T &x) {
  scanf("%d", &x);
}
template <class T>
inline void OT(const T &x) {
  printf("%d\n", x);
}
const int N = 100001, M = 2 * N;
int l[N], r[N], p[N], w0[N], w1[N], w2[N], rev[N], rt[N];
int hd[N], nxt[M], del[M], b[M];
int cir[N], idx[N], rmv, cn;
int P[N];
int Find(int x) { return P[x] == x ? x : P[x] = Find(P[x]); }
int n, m, cpt;
inline void Rev(int x) {
  if (x == 0) return;
  w0[x] ^= 1, swap(w1[x], w2[x]), rev[x] ^= 1;
}
inline void Release(int x) {
  if (x == 0) return;
  if (rev[x]) {
    Rev(l[x]), Rev(r[x]), rev[x] = 0;
  }
}
inline void Update(int x) {
  w1[x] = w1[l[x]] + w1[r[x]] + w0[x];
  w2[x] = w2[l[x]] + w2[r[x]] + (w0[x] ^ 1);
}
inline void Set(int l[], int y, int x) { l[y] = x, p[x] = y; }
inline void Rotate(int x) {
  int y = p[x];
  if (!rt[y])
    Release(p[y]), Set(y == l[p[y]] ? l : r, p[y], x);
  else
    p[x] = p[y];
  Release(y), Release(x);
  if (x == l[y])
    Set(l, y, r[x]), Set(r, x, y);
  else
    Set(r, y, l[x]), Set(l, x, y);
  if (rt[y]) rt[y] = false, rt[x] = true;
  Update(y);
}
inline void Splay(int x) {
  while (!rt[x]) Rotate(x);
}
void Access(int x) {
  int y = 0;
  do {
    Splay(x), Release(x);
    rt[r[x]] = true, rt[r[x] = y] = false, Update(x);
    x = p[y = x];
  } while (x);
}
void Reverse(int x) {
  Access(x), Splay(x = cir[0]);
  cpt += w1[r[x]] - w2[r[x]], Rev(r[x]);
}
inline int C() {
  int x;
  Access(cir[1]), Splay(x = cir[0]);
  return w1[r[x]] + rmv;
}
int top;
inline void dfs1(int u = 1) {
  rt[p[++top] = u] = top;
  for (int i = hd[u]; i; i = nxt[i])
    if (!del[i]) {
      del[i ^ 1] = true;
      if (rt[b[i]]) {
        for (int j = int(rt[b[i]]); j <= int(top); ++j)
          idx[cir[++cn] = p[j]] = cn;
        cir[0] = cir[cn], cir[cn + 1] = cir[1], rmv = i >> 1;
      } else {
        dfs1(b[i]);
      }
    }
  --top;
}
inline void dfs2(int u = cir[0]) {
  for (int i = hd[u]; i; i = nxt[i])
    if (i >> 1 != rmv && !p[b[i]]) {
      p[b[i]] = u, dfs2(b[i]);
    }
}
int main() {
  RD(n, m);
  for (int i = 2; i <= n << 1; i += 2) {
    RD(b[i | 1], b[i]), nxt[i] = hd[b[i | 1]], hd[b[i | 1]] = i;
    nxt[i | 1] = hd[b[i]], hd[b[i]] = i | 1;
  }
  dfs1(), RST(p), p[cir[0]] = -1, dfs2(), p[cir[0]] = 0;
  for (int i = 1; i <= int(n); ++i) P[i] = idx[i] ? i : p[i];
  for (int i = 1; i <= int(n); ++i) Find(i);
  cpt = n, rmv = 0;
  int a, b;
  while (m--) {
    RD(a, b), Reverse(a), Reverse(b);
    if (abs(idx[P[a]] - idx[P[b]]) > (cn - abs(idx[P[a]] - idx[P[b]])) ||
        abs(idx[P[a]] - idx[P[b]]) == (cn - abs(idx[P[a]] - idx[P[b]])) &&
            (idx[P[a]] < idx[P[b]] ? cir[idx[P[a]] + 1] : cir[idx[P[a]] - 1]) >
                (idx[P[a]] < idx[P[b]] ? cir[idx[P[a]] - 1]
                                       : cir[idx[P[a]] + 1])) {
      rmv ^= 1, cpt -= rmv ? 1 : -1;
      Reverse(cir[1]);
    }
    OT(cpt + (C() == cn));
  }
}
