func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MX = 500000;   int m, i, j, ii;   long long l, r, k, R, h, s, a[2][2], b[2][2], f[2][2];   void upd(long long h) {     if (r / h - (l - 1) / h >= k) R = max(R, h);   }   int main() {     scanf( %d%I64d%I64d%I64d , &m, &l, &r, &k);     for (h = 1; h <= MX; h++) upd(h);     for (h = 1; r / h > MX; h++) upd(r / h);     for (h = 1; (l - 1) / h > MX; h++) upd((l - 1) / h);     R--;     a[0][0] = 0;     a[0][1] = 1 % m;     a[1][0] = 1 % m;     a[1][1] = 1;     f[0][0] = 1 % m;     f[0][1] = 0;     f[1][0] = 0;     f[1][1] = 1 % m;     for (ii = 60; ii >= 0; ii--) {       for (i = 0; i < 2; i++)         for (j = 0; j < 2; j++) {           b[i][j] = 0;           for (int k = 0; k < 2; k++) b[i][j] = (b[i][j] + f[i][k] * f[k][j]) % m;         }       if (R & (1LL << ii))         for (i = 0; i < 2; i++)           for (j = 0; j < 2; j++) {             f[i][j] = 0;             for (int k = 0; k < 2; k++)               f[i][j] = (f[i][j] + b[i][k] * a[k][j]) % m;           }       else         for (i = 0; i < 2; i++)           for (j = 0; j < 2; j++) f[i][j] = b[i][j];     }     printf( %I64d n , f[1][1] % m);     return 0;   }   