import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.NoSuchElementException; public class Main implements Runnable { public static void main(String[] args) { // new Thread(null, new Main(), "", Runtime.getRuntime().maxMemory()).start(); new Main().run(); } long pow(long a, long n) { if (n == 0) return 1; return pow(a*a,n/2)*(n%2==1?a:1); } long pow_mod(long a, long n, long mod) { a %= mod; if (n == 0) return 1; return pow_mod(a * a % mod, n / 2, mod) * (n % 2 == 1 ? a : 1) % mod; } long inv(long a, long mod, long ord) { return pow_mod(a, ord-1, mod); } long gcd(long a, long b) { if (a == 0) return b; else return gcd(b % a, a); } public void run() { FastScanner sc = new FastScanner(); PrintWriter pw=new PrintWriter(System.out); long L = sc.nextLong(); long R = sc.nextLong(); long M = sc.nextLong(); pw.println(solve(L, R, M)); pw.close(); } long[][] rec = new long[100][100]; void init() { for (int i = 0; i < rec.length; ++i) { for (int j = 0; j < rec[i].length; ++j) { rec[i][j] = -1; } } } long c(long n, long k, long mod) { if (k<0||n-k<0) return 0; if (k == 0 || k == n) return 1; if (rec[(int)n][(int)k] != -1) return rec[(int)n][(int)k]; return rec[(int)n][(int)k] = (c(n-1, k, mod) + c(n-1, k-1, mod))%mod; } long exact(long L, long R, long M) { init(); long ret = 0; for (long n = L; n <= R; ++n) { ret = (ret + c(2 * n, n, M))% M; } ret = (ret % M + M) % M; return ret; } long coprime(long a, long m) { while (gcd(a, m) != 1) { a /= gcd(a, m); } return a; } List> factor(long n) { ArrayList primes = new ArrayList<>(); ArrayList indexes = new ArrayList<>(); for (long i = 2; i * i <= n; ++i) { int e = 0; while (n % i == 0) { n /= i; ++e; } if (e != 0) { primes.add(i); indexes.add(e); } } if (n != 1) { primes.add(n); indexes.add(1); } return List.of(primes, indexes); } long solve(long L, long R, long M) { if (M == 1) return 0; var factor = factor(M); ArrayList primes = (ArrayList) factor.get(0); ArrayList indexes = (ArrayList) factor.get(1); ArrayList pes = new ArrayList<>(); for (int i = 0; i < primes.size(); ++i) pes.add(pow(primes.get(i), indexes.get(i))); long[] v = new long[primes.size()]; for (int i = 0; i < primes.size(); ++i) { int p = primes.get(i).intValue(); int pe = (int) pow(primes.get(i), indexes.get(i)); long[] fac = new long[pe + 1]; long[] ifac = new long[fac.length]; Arrays.fill(fac, 1); Arrays.fill(ifac, 1); for (int j = 1; j < fac.length; ++j) fac[j] = (j % p == 0 ? 1 : j ) * fac[j - 1] % pe; ifac[fac.length - 1] = fac[fac.length - 1]; for (int j = ifac.length - 1; j >= 1; --j) ifac[j - 1] = (j % p == 0 ? 1 : j ) * ifac[j] % pe; for (long n = L; n <= R; ++n) { long comb = 1; long e = 0; long f = 0; { long a = 2 * n; long b = n; do { comb = comb * fac[(int) (a%pe)] % pe * ifac[(int) (b%pe)] % pe * ifac[(int) (b%pe)] % pe; f += a / pe - b / pe * 2; e += a / p - b / p * 2; a /= p; b /= p; } while (a != 0); } e = Math.min(e, indexes.get(i)); comb = comb * pes.get(i); comb = comb * (f % 2 == 1 ? fac[fac.length - 1] : 1); v[i] = (v[i] + comb) % pe; } } for (long i = 0; i < M; ++i) { boolean ok = true; for (int j = 0; j < primes.size(); ++j) { ok &= v[j] == i % pes.get(j); } if (ok) { long ans = i - 2 * (R - L + 1); ans = (ans % M + M) % M; return ans; } } throw new AssertionError(); } void tr(Object... objects) { System.err.println(Arrays.deepToString(objects)); } } class FastScanner { private final InputStream in = System.in; private final byte[] buffer = new byte[1024]; private int ptr = 0; private int buflen = 0; private boolean hasNextByte() { if (ptr < buflen) { return true; } else { ptr = 0; try { buflen = in.read(buffer); } catch (IOException e) { e.printStackTrace(); } if (buflen <= 0) { return false; } } return true; } private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1; } private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126; } private void skipUnprintable() { while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; } public boolean hasNext() { skipUnprintable(); return hasNextByte(); } public String next() { if (!hasNext()) throw new NoSuchElementException(); StringBuilder sb = new StringBuilder(); int b = readByte(); while (isPrintableChar(b)) { sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } public long nextLong() { if (!hasNext()) throw new NoSuchElementException(); long n = 0; boolean minus = false; int b = readByte(); if (b == '-') { minus = true; b = readByte(); } if (b < '0' || '9' < b) { throw new NumberFormatException(); } while (true) { if ('0' <= b && b <= '9') { n *= 10; n += b - '0'; } else if (b == -1 || !isPrintableChar(b)) { return minus ? -n : n; } else { throw new NumberFormatException(); } b = readByte(); } } public int nextInt() { return (int) nextLong(); } }