#line 1 "test.cpp"
//#pragma GCC target("avx2")
//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <debug.hpp>
#define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) (static_cast<void>(0))
#endif
using ll = long long;
using ld = long double;
using pll = pair<ll,ll>;
using pii = pair<int,int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vpii = vector<pii>;
using vpll = vector<pll>;
using vs = vector<string>;
template<class T> using pq = priority_queue<T,vector<T>,greater<T>>;
#define overload4(_1, _2, _3, _4, name, ...) name
#define overload3(a,b,c,name,...) name
#define rep1(n) for (ll UNUSED_NUMBER = 0; UNUSED_NUMBER < (n); ++UNUSED_NUMBER)
#define rep2(i, n) for (ll i = 0; i < (n); ++i)
#define rep3(i, a, b) for (ll i = (a); i < (b); ++i)
#define rep4(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep1(n) for(ll i = (n) - 1;i >= 0;i--)
#define rrep2(i,n) for(ll i = (n) - 1;i >= 0;i--)
#define rrep3(i,a,b) for(ll i = (b) - 1;i >= (a);i--)
#define rrep4(i,a,b,c) for(ll i = (a) + ((b)-(a)-1) / (c) * (c);i >= (a);i -= c)
#define rrep(...) overload4(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)
#define all1(i) begin(i),end(i)
#define all2(i,a) begin(i),begin(i)+a
#define all3(i,a,b) begin(i)+a,begin(i)+b
#define all(...) overload3(__VA_ARGS__, all3, all2, all1)(__VA_ARGS__)
#define sum(...) accumulate(all(__VA_ARGS__),0LL)
template<class T> bool chmin(T &a, const T &b){ if(a > b){ a = b; return 1; } else return 0; }
template<class T> bool chmax(T &a, const T &b){ if(a < b){ a = b; return 1; } else return 0; }
template<class T> auto min(const T& a){ return *min_element(all(a)); }
template<class T> auto max(const T& a){ return *max_element(all(a)); }
template<class... Ts> void in(Ts&... t);
#define INT(...) int __VA_ARGS__; in(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__; in(__VA_ARGS__)
#define STR(...) string __VA_ARGS__; in(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__; in(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__; in(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__; in(__VA_ARGS__)
#define VEC(type, name, size) vector<type> name(size); in(name)
#define VV(type, name, h, w) vector<vector<type>> name(h, vector<type>(w)); in(name)
ll intpow(ll a, ll b){ ll ans = 1; while(b){if(b & 1) ans *= a; a *= a; b /= 2;} return ans;}
ll modpow(ll a, ll b, ll p){ ll ans = 1; a %= p;while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; }
ll GCD(ll a,ll b) { if(a == 0 || b == 0) return a + b; if(a % b == 0) return b; else return GCD(b,a%b);}
ll LCM(ll a,ll b) { if(a == 0) return b; if(b == 0) return a;return a / GCD(a,b) * b;}
namespace IO{
#define VOID(a) decltype(void(a))
struct setting{ setting(){cin.tie(nullptr); ios::sync_with_stdio(false);fixed(cout); cout.precision(12);}} setting;
template<int I> struct P : P<I-1>{};
template<> struct P<0>{};
template<class T> void i(T& t){ i(t, P<3>{}); }
void i(vector<bool>::reference t, P<3>){ int a; i(a); t = a; }
template<class T> auto i(T& t, P<2>) -> VOID(cin >> t){ cin >> t; }
template<class T> auto i(T& t, P<1>) -> VOID(begin(t)){ for(auto&& x : t) i(x); }
template<class T, size_t... idx> void ituple(T& t, index_sequence<idx...>){
    in(get<idx>(t)...);}
template<class T> auto i(T& t, P<0>) -> VOID(tuple_size<T>{}){
    ituple(t, make_index_sequence<tuple_size<T>::value>{});}
#undef VOID
}
#define unpack(a) (void)initializer_list<int>{(a, 0)...}
template<class... Ts> void in(Ts&... t){ unpack(IO :: i(t)); }
#undef unpack
constexpr int mod = 1000000007;
//constexpr int mod = 998244353;
static const double PI = 3.1415926535897932;
template <class F> struct REC {
    F f;
    REC(F &&f_) : f(forward<F>(f_)) {}
    template <class... Args> auto operator()(Args &&...args) const { return f(*this, forward<Args>(args)...); }};

#line 2 "modulo/arbitrary-mod-binomial.hpp"

#line 89 "test.cpp"

#line 1 "atcoder/math.hpp"



#line 97 "test.cpp"
#line 8 "atcoder/math.hpp"

#line 1 "atcoder/internal_math.hpp"



#line 104 "test.cpp"

#ifdef _MSC_VER
#include <intrin.h>
#endif

namespace atcoder {

namespace internal {

// @param m `1 <= m`
// @return x mod m
constexpr long long safe_mod(long long x, long long m) {
    x %= m;
    if (x < 0) x += m;
    return x;
}

// Fast modular multiplication by barrett reduction
// Reference: https://en.wikipedia.org/wiki/Barrett_reduction
// NOTE: reconsider after Ice Lake
struct barrett {
    unsigned int _m;
    unsigned long long im;

    // @param m `1 <= m < 2^31`
    barrett(unsigned int m) : _m(m), im((unsigned long long)(-1) / m + 1) {}

    // @return m
    unsigned int umod() const { return _m; }

    // @param a `0 <= a < m`
    // @param b `0 <= b < m`
    // @return `a * b % m`
    unsigned int mul(unsigned int a, unsigned int b) const {
        // [1] m = 1
        // a = b = im = 0, so okay

        // [2] m >= 2
        // im = ceil(2^64 / m)
        // -> im * m = 2^64 + r (0 <= r < m)
        // let z = a*b = c*m + d (0 <= c, d < m)
        // a*b * im = (c*m + d) * im = c*(im*m) + d*im = c*2^64 + c*r + d*im
        // c*r + d*im < m * m + m * im < m * m + 2^64 + m <= 2^64 + m * (m + 1) < 2^64 * 2
        // ((ab * im) >> 64) == c or c + 1
        unsigned long long z = a;
        z *= b;
#ifdef _MSC_VER
        unsigned long long x;
        _umul128(z, im, &x);
#else
        unsigned long long x =
            (unsigned long long)(((unsigned __int128)(z)*im) >> 64);
#endif
        unsigned int v = (unsigned int)(z - x * _m);
        if (_m <= v) v += _m;
        return v;
    }
};

// @param n `0 <= n`
// @param m `1 <= m`
// @return `(x ** n) % m`
constexpr long long pow_mod_constexpr(long long x, long long n, int m) {
    if (m == 1) return 0;
    unsigned int _m = (unsigned int)(m);
    unsigned long long r = 1;
    unsigned long long y = safe_mod(x, m);
    while (n) {
        if (n & 1) r = (r * y) % _m;
        y = (y * y) % _m;
        n >>= 1;
    }
    return r;
}

// Reference:
// M. Forisek and J. Jancina,
// Fast Primality Testing for Integers That Fit into a Machine Word
// @param n `0 <= n`
constexpr bool is_prime_constexpr(int n) {
    if (n <= 1) return false;
    if (n == 2 || n == 7 || n == 61) return true;
    if (n % 2 == 0) return false;
    long long d = n - 1;
    while (d % 2 == 0) d /= 2;
    constexpr long long bases[3] = {2, 7, 61};
    for (long long a : bases) {
        long long t = d;
        long long y = pow_mod_constexpr(a, t, n);
        while (t != n - 1 && y != 1 && y != n - 1) {
            y = y * y % n;
            t <<= 1;
        }
        if (y != n - 1 && t % 2 == 0) {
            return false;
        }
    }
    return true;
}
template <int n> constexpr bool is_prime = is_prime_constexpr(n);

// @param b `1 <= b`
// @return pair(g, x) s.t. g = gcd(a, b), xa = g (mod b), 0 <= x < b/g
constexpr std::pair<long long, long long> inv_gcd(long long a, long long b) {
    a = safe_mod(a, b);
    if (a == 0) return {b, 0};

    // Contracts:
    // [1] s - m0 * a = 0 (mod b)
    // [2] t - m1 * a = 0 (mod b)
    // [3] s * |m1| + t * |m0| <= b
    long long s = b, t = a;
    long long m0 = 0, m1 = 1;

    while (t) {
        long long u = s / t;
        s -= t * u;
        m0 -= m1 * u;  // |m1 * u| <= |m1| * s <= b

        // [3]:
        // (s - t * u) * |m1| + t * |m0 - m1 * u|
        // <= s * |m1| - t * u * |m1| + t * (|m0| + |m1| * u)
        // = s * |m1| + t * |m0| <= b

        auto tmp = s;
        s = t;
        t = tmp;
        tmp = m0;
        m0 = m1;
        m1 = tmp;
    }
    // by [3]: |m0| <= b/g
    // by g != b: |m0| < b/g
    if (m0 < 0) m0 += b / s;
    return {s, m0};
}

// Compile time primitive root
// @param m must be prime
// @return primitive root (and minimum in now)
constexpr int primitive_root_constexpr(int m) {
    if (m == 2) return 1;
    if (m == 167772161) return 3;
    if (m == 469762049) return 3;
    if (m == 754974721) return 11;
    if (m == 998244353) return 3;
    int divs[20] = {};
    divs[0] = 2;
    int cnt = 1;
    int x = (m - 1) / 2;
    while (x % 2 == 0) x /= 2;
    for (int i = 3; (long long)(i)*i <= x; i += 2) {
        if (x % i == 0) {
            divs[cnt++] = i;
            while (x % i == 0) {
                x /= i;
            }
        }
    }
    if (x > 1) {
        divs[cnt++] = x;
    }
    for (int g = 2;; g++) {
        bool ok = true;
        for (int i = 0; i < cnt; i++) {
            if (pow_mod_constexpr(g, (m - 1) / divs[i], m) == 1) {
                ok = false;
                break;
            }
        }
        if (ok) return g;
    }
}
template <int m> constexpr int primitive_root = primitive_root_constexpr(m);

}  // namespace internal

}  // namespace atcoder


#line 10 "atcoder/math.hpp"

namespace atcoder {

long long pow_mod(long long x, long long n, int m) {
    assert(0 <= n && 1 <= m);
    if (m == 1) return 0;
    internal::barrett bt((unsigned int)(m));
    unsigned int r = 1, y = (unsigned int)(internal::safe_mod(x, m));
    while (n) {
        if (n & 1) r = bt.mul(r, y);
        y = bt.mul(y, y);
        n >>= 1;
    }
    return r;
}

long long inv_mod(long long x, long long m) {
    assert(1 <= m);
    auto z = internal::inv_gcd(x, m);
    assert(z.first == 1);
    return z.second;
}

// (rem, mod)
std::pair<long long, long long> crt(const std::vector<long long>& r,
                                    const std::vector<long long>& m) {
    assert(r.size() == m.size());
    int n = int(r.size());
    // Contracts: 0 <= r0 < m0
    long long r0 = 0, m0 = 1;
    for (int i = 0; i < n; i++) {
        assert(1 <= m[i]);
        long long r1 = internal::safe_mod(r[i], m[i]), m1 = m[i];
        if (m0 < m1) {
            std::swap(r0, r1);
            std::swap(m0, m1);
        }
        if (m0 % m1 == 0) {
            if (r0 % m1 != r1) return {0, 0};
            continue;
        }
        // assume: m0 > m1, lcm(m0, m1) >= 2 * max(m0, m1)

        // (r0, m0), (r1, m1) -> (r2, m2 = lcm(m0, m1));
        // r2 % m0 = r0
        // r2 % m1 = r1
        // -> (r0 + x*m0) % m1 = r1
        // -> x*u0*g % (u1*g) = (r1 - r0) (u0*g = m0, u1*g = m1)
        // -> x = (r1 - r0) / g * inv(u0) (mod u1)

        // im = inv(u0) (mod u1) (0 <= im < u1)
        long long g, im;
        std::tie(g, im) = internal::inv_gcd(m0, m1);

        long long u1 = (m1 / g);
        // |r1 - r0| < (m0 + m1) <= lcm(m0, m1)
        if ((r1 - r0) % g) return {0, 0};

        // u1 * u1 <= m1 * m1 / g / g <= m0 * m1 / g = lcm(m0, m1)
        long long x = (r1 - r0) / g % u1 * im % u1;

        // |r0| + |m0 * x|
        // < m0 + m0 * (u1 - 1)
        // = m0 + m0 * m1 / g - m0
        // = lcm(m0, m1)
        r0 += x * m0;
        m0 *= u1;  // -> lcm(m0, m1)
        if (r0 < 0) r0 += m0;
    }
    return {r0, m0};
}

long long floor_sum(long long n, long long m, long long a, long long b) {
    long long ans = 0;
    if (a >= m) {
        ans += (n - 1) * n * (a / m) / 2;
        a %= m;
    }
    if (b >= m) {
        ans += n * (b / m);
        b %= m;
    }

    long long y_max = (a * n + b) / m, x_max = (y_max * m - b);
    if (y_max == 0) return ans;
    ans += (n - (x_max + a - 1) / a) * y_max;
    ans += floor_sum(y_max, a, m, (a - x_max % a) % a);
    return ans;
}

}  // namespace atcoder


#line 2 "modint/barrett-reduction.hpp"

#line 4 "modint/barrett-reduction.hpp"
using namespace std;

struct Barrett {
  using u32 = unsigned int;
  using i64 = long long;
  using u64 = unsigned long long;
  u32 m;
  u64 im;
  Barrett() : m(), im() {}
  Barrett(int n) : m(n), im(u64(-1) / m + 1) {}
  constexpr inline i64 quo(u64 n) {
    u64 x = u64((__uint128_t(n) * im) >> 64);
    u32 r = n - x * m;
    return m <= r ? x - 1 : x;
  }
  constexpr inline i64 rem(u64 n) {
    u64 x = u64((__uint128_t(n) * im) >> 64);
    u32 r = n - x * m;
    return m <= r ? r + m : r;
  }
  constexpr inline pair<i64, int> quorem(u64 n) {
    u64 x = u64((__uint128_t(n) * im) >> 64);
    u32 r = n - x * m;
    if (m <= r) return {x - 1, r + m};
    return {x, r};
  }
  constexpr inline i64 pow(u64 n, i64 p) {
    u32 a = rem(n), r = m == 1 ? 0 : 1;
    while (p) {
      if (p & 1) r = rem(u64(r) * a);
      a = rem(u64(a) * a);
      p >>= 1;
    }
    return r;
  }
};
#line 7 "modulo/arbitrary-mod-binomial.hpp"

using namespace std;

#define PRIME_POWER_BINOMIAL_M_MAX ((1LL << 30) - 1)
#define PRIME_POWER_BINOMIAL_N_MAX 20000000

struct prime_power_binomial {
  int p, q, M;
  vector<int> fac, ifac, inv;
  int delta;
  Barrett bm, bp;

  prime_power_binomial(int _p, int _q) : p(_p), q(_q) {
    assert(1 < p && p <= PRIME_POWER_BINOMIAL_M_MAX);
    assert(_q > 0);
    long long m = 1;
    while (_q--) {
      m *= p;
      assert(m <= PRIME_POWER_BINOMIAL_M_MAX);
    }
    M = m;
    bm = Barrett(M), bp = Barrett(p);
    enumerate();
    delta = (p == 2 && q >= 3) ? 1 : M - 1;
  }

  void enumerate() {
    int MX = min<int>(M, PRIME_POWER_BINOMIAL_N_MAX + 10);
    fac.resize(MX);
    ifac.resize(MX);
    inv.resize(MX);
    fac[0] = ifac[0] = inv[0] = 1;
    fac[1] = ifac[1] = inv[1] = 1;
    for (int i = 2; i < MX; i++) {
      if (i % p == 0) {
        fac[i] = fac[i - 1];
        fac[i + 1] = bm.rem(1LL * fac[i - 1] * (i + 1));
        i++;
      } else {
        fac[i] = bm.rem(1LL * fac[i - 1] * i);
      }
    }
    ifac[MX - 1] = bm.pow(fac[MX - 1], M / p * (p - 1) - 1);
    for (int i = MX - 2; i > 1; --i) {
      if (i % p == 0) {
        ifac[i] = bm.rem(1LL * ifac[i + 1] * (i + 1));
        ifac[i - 1] = ifac[i];
        i--;
      } else {
        ifac[i] = bm.rem(1LL * ifac[i + 1] * (i + 1));
      }
    }
  }

  long long Lucas(long long n, long long m) {
    int res = 1;
    while (n) {
      int n0, m0;
      tie(n, n0) = bp.quorem(n);
      tie(m, m0) = bp.quorem(m);
      if (n0 < m0) return 0;
      res = bm.rem(1LL * res * fac[n0]);
      int buf = bm.rem(1LL * ifac[n0 - m0] * ifac[m0]);
      res = bm.rem(1LL * res * buf);
    }
    return res;
  }

  long long C(long long n, long long m) {
    if (n < m || n < 0 || m < 0) return 0;
    if (q == 1) return Lucas(n, m);
    long long r = n - m;
    int e0 = 0, eq = 0, i = 0;
    int res = 1;
    while (n) {
      res = bm.rem(1LL * res * fac[bm.rem(n)]);
      res = bm.rem(1LL * res * ifac[bm.rem(m)]);
      res = bm.rem(1LL * res * ifac[bm.rem(r)]);
      n = bp.quo(n);
      m = bp.quo(m);
      r = bp.quo(r);
      int eps = n - m - r;
      e0 += eps;
      if (e0 >= q) return 0;
      if (++i >= q) eq += eps;
    }
    if (eq & 1) res = bm.rem(1LL * res * delta);
    res = bm.rem(1LL * res * bm.pow(p, e0));
    return res;
  }
};

// constraints:
// (M <= 1e7 and max(N) <= 1e18) or (M < 2^30 and max(N) <= 2e7)
struct arbitrary_mod_binomial {
  int mod;
  vector<int> M;
  vector<prime_power_binomial> cs;

  arbitrary_mod_binomial(long long md) : mod(md) {
    assert(1 <= md);
    assert(md <= PRIME_POWER_BINOMIAL_M_MAX);
    for (int i = 2; i * i <= md; i++) {
      if (md % i == 0) {
        int j = 0, k = 1;
        while (md % i == 0) md /= i, j++, k *= i;
        M.push_back(k);
        cs.emplace_back(i, j);
        assert(M.back() == cs.back().M);
      }
    }
    if (md != 1) {
      M.push_back(md);
      cs.emplace_back(md, 1);
    }
    assert(M.size() == cs.size());
  }

  long long C(long long n, long long m) {
    if (mod == 1) return 0;
    vector<long long> rem, d;
    for (int i = 0; i < (int)cs.size(); i++) {
      rem.push_back(cs[i].C(n, m));
      d.push_back(M[i]);
    }
    return atcoder::crt(rem, d).first;
  }
};

#undef PRIME_POWER_BINOMIAL_M_MAX
#undef PRIME_POWER_BINOMIAL_N_MAX

/**
 * @brief 任意mod二項係数
 * @docs docs/modulo/arbitrary-mod-binomial.md
 */

#line 2 "library/modint/ArbitaryModint.hpp"
//#include "library/modint/barrett-reduction.hpp"
struct ArbitraryModint {
    int x;
    ArbitraryModint():x(0) {}
    ArbitraryModint(int64_t y) {
        int z = y % get_mod();
        if(z < 0) z += get_mod();
        x = z;
    }
    ArbitraryModint &operator+=(const ArbitraryModint &p) {
        if((x += p.x) >= get_mod()) x -= get_mod();
        return *this;
    }
    ArbitraryModint &operator-=(const ArbitraryModint &p) {
        if((x += get_mod() - p.x) >= get_mod()) x -= get_mod();
        return *this;
    }
    ArbitraryModint &operator*=(const ArbitraryModint &p) {
        x = rem((unsigned long long)x * p.x);
        return *this;
    }
    ArbitraryModint &operator/=(const ArbitraryModint &p) {
        *this *= p.inverse();
        return *this;
    }
    ArbitraryModint operator-() const {return ArbitraryModint(-x);};
    ArbitraryModint operator+(const ArbitraryModint &p) const{
        return ArbitraryModint(*this) += p;
    }
    ArbitraryModint operator-(const ArbitraryModint &p) const{
        return ArbitraryModint(*this) -= p;
    }
    ArbitraryModint operator*(const ArbitraryModint &p) const{
        return ArbitraryModint(*this) *= p;
    }
    ArbitraryModint operator/(const ArbitraryModint &p) const {
        return ArbitraryModint(*this) /= p;
    }
    bool operator==(const ArbitraryModint &p) {return x == p.x;}
    bool operator!=(const ArbitraryModint &p) {return x != p.x;}
    ArbitraryModint inverse() const {
        int a = x,b = get_mod(),u = 1,v = 0,t;
        while(b > 0) {
            t = a / b;
            swap(a -= t * b,b);
            swap(u -= t * v,v);
        }
        return ArbitraryModint(u);
    }
    ArbitraryModint pow(int64_t n) const {
        ArbitraryModint ret(1),mul(x);
        while(n > 0) {
            if(n & 1) ret *= mul;
            mul *= mul;
            n >>= 1;
        }
        return ret;
    }
    friend ostream &operator<<(ostream &os,const ArbitraryModint &p) {
        return os << p.x;
    }
    friend istream &operator>>(istream &is,ArbitraryModint &a) {
        int64_t t;
        is >> t;
        a = ArbitraryModint(t);
        return (is);
    }
    int get() const {return x;}
    inline unsigned int rem(unsigned long long p) {return barrett().rem(p);};
    static inline Barrett &barrett() {
        static Barrett b;
        return b;
    }
    static inline int &get_mod() {
        static int mod = 0;
        return mod;
    }
    static void set_mod(int md) {
        assert(0 < md && md <= (1LL << 30) - 1);
        get_mod() = md;
        barrett() = Barrett(md);
    }
};
#line 556 "test.cpp"
using mint = ArbitraryModint;

int main() {
    LL(L,R);
    INT(m);
    arbitrary_mod_binomial C(m);
    mint::set_mod(m);
    mint ans;
    rep(i,L,R+1) {
        ans += C.C(2*i,i);
    }
    ans -= (R - L + 1) * 2;
    cout << ans << '\n';
}