#include "pilgrimage.h"
#include<bits/stdc++.h>
#define int long long
using namespace std;
inline int read() {
    int x = 0;
    char c = getchar();
    bool f = 0;
    while(!isdigit(c)) f |= (c == '-'), c = getchar();
    while(isdigit(c)) x = (x * 10) + (c ^ 48), c = getchar();
    return f ? -x : x;
}
const int maxn = 3000 + 5;
int mod;
int f[maxn][maxn << 1], Answer[maxn], Inv2, Inv4;
inline int Ksm(int x, int y) {
    int res = 1;
    while(y) {
        if(y & 1) res = res * x % mod;
        x = x * x % mod;
    }
    return res;
}
inline int Calc(int x) { return Ksm(x, mod - 2); }
inline int ask(int n) { return Answer[n]; }
inline void init(int o, int p) {
    mod = p;
    f[0][3000] = 1, Inv2 = Calc(2), Inv4 = Calc(4);
    for(register int i = 1; i <= 3000; ++i)
        for(register int j = 3000 - i; j <= 3000 + i; ++j)
            f[i][j] = (f[i - 1][j - 1] * Inv4 % mod + f[i - 1][j] * Inv2 % mod + f[i - 1][j + 1] * Inv4 % mod) % mod;
    for(register int i = 1; i <= 3000; ++i) {
        for(register int j = 3000 - i; j <= 3000 + i; ++j) Answer[i] = (Answer[i] + f[i][i - j] * abs(j - 3000) % mod) % mod;
    }
}

answer.code:25:12: error: ambiguating new declaration of ‘long long int ask(long long int)’
   25 | inline int ask(int n) { return Answer[n]; }
      |            ^~~
In file included from answer.code:1:
pilgrimage.h:3:5: note: old declaration ‘int ask(long long int)’
    3 | int ask (long long n);
      |     ^~~