Language: C++

#include <bits/stdc++.h>
using namespace std;
  
// Macro Tools /////////////////////////////////////////////////////////////////
#define GET_MACRO_09(A0, A1, A2, A3, A4, A5, A6, A7, A8, NAME, ...) NAME
  
#define EXPAND_01(MACRO, A0, ...) \
    MACRO(A0, ##__VA_ARGS__) 
#define EXPAND_02(MACRO, A0, A1, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) 
#define EXPAND_03(MACRO, A0, A1, A2, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__) 
#define EXPAND_04(MACRO, A0, A1, A2, A3, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) 
#define EXPAND_05(MACRO, A0, A1, A2, A3, A4, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) MACRO(A4, ##__VA_ARGS__) 
#define EXPAND_06(MACRO, A0, A1, A2, A3, A4, A5, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) MACRO(A4, ##__VA_ARGS__) MACRO(A5, ##__VA_ARGS__) 
#define EXPAND_07(MACRO, A0, A1, A2, A3, A4, A5, A6, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) MACRO(A4, ##__VA_ARGS__) MACRO(A5, ##__VA_ARGS__)  \
    MACRO(A6, ##__VA_ARGS__) 
#define EXPAND_08(MACRO, A0, A1, A2, A3, A4, A5, A6, A7, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) MACRO(A4, ##__VA_ARGS__) MACRO(A5, ##__VA_ARGS__)  \
    MACRO(A6, ##__VA_ARGS__) MACRO(A7, ##__VA_ARGS__) 
#define EXPAND_09(MACRO, A0, A1, A2, A3, A4, A5, A6, A7, A8, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) MACRO(A4, ##__VA_ARGS__) MACRO(A5, ##__VA_ARGS__)  \
    MACRO(A6, ##__VA_ARGS__) MACRO(A7, ##__VA_ARGS__) MACRO(A8, ##__VA_ARGS__) 
  
#define GET_EXPAND(...) GET_MACRO_09(__VA_ARGS__, EXPAND_09, EXPAND_08, \
    EXPAND_07, EXPAND_06, EXPAND_05, EXPAND_04, EXPAND_03, EXPAND_02, EXPAND_01)
#define EXPAND_ARG_0(MACRO, ...) GET_EXPAND(__VA_ARGS__)(MACRO, __VA_ARGS__)
#define EXPAND_ARG_1(MACRO, A0, ...) GET_EXPAND(__VA_ARGS__)(MACRO, __VA_ARGS__, A0)
  
#define EXPAND(MACRO, ...) EXPAND_ARG_0(MACRO, __VA_ARGS__)
  
#define Q(x) #x
#define QUOTE(x) Q(x)

// Input ///////////////////////////////////////////////////////////////////////
#define SCANF_INT(a) scanf("%d", &(a));
#define ID(...) int __VA_ARGS__;
#define IR(...) {EXPAND(SCANF_INT, __VA_ARGS__)}
#define I(...) ID(__VA_ARGS__) IR(__VA_ARGS__)
  
// #define DEFINE_INT_ARRAY(a, n) int a[n];
// #define INT_ITH_ARRAY(a, i) a[i]
// #define IAD(N, ...) EXPAND_ARG_1(DEFINE_INT_ARRAY, N, __VA_ARGS__)
// #define IAR(N, ...) REP(array_reader_i, N){ 
  
#define SCANF_LL(a) scanf("%lld", &(a));
#define LD(...) ll __VA_ARGS__;
#define LR(...) {EXPAND(SCANF_LL, __VA_ARGS__)}
#define L(...) LD(__VA_ARGS__) LR(__VA_ARGS__)
  
#define SCANF_LD(a) scanf("%Lf", &(a));
#define DD(...) lD __VA_ARGS__;
#define DR(...) {EXPAND(SCANF_LD, __VA_ARGS__)}
#define D(...) DD(__VA_ARGS__) DR(__VA_ARGS__)
  
#define DEFINE_STR(a, n) char a[n];
#define SCANF_STR(a) scanf("%s", a);
#define SD(N, ...) EXPAND_ARG_1(DEFINE_STR, N, __VA_ARGS__)
#define SR(...) EXPAND(SCANF_STR, __VA_ARGS__)
#define S(N, ...) SD(N, __VA_ARGS__) SR(__VA_ARGS__)
  
// Output //////////////////////////////////////////////////////////////////////
#define LN printf("\n")
#define FL fflush(stdout)
  
#define IP(a, ...) printf("%d", a); 
  
// Types ///////////////////////////////////////////////////////////////////////
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<int, ll> pil;
typedef pair<ll, int> pli;
typedef pair<ll, ll> pll;
typedef set<int> si;
typedef set<ll> sll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef list<int> li;
typedef list<ll> lll;
typedef map<int, int> mii;
typedef map<int, ll> mil;
typedef map<ll, int> mli;
typedef map<ll, ll> mll;
  
// Loop & Iteration ////////////////////////////////////////////////////////////
#define FORT(t, i, a, b) \
    for(t i = (a), loop_end_##i=(b); i < (loop_end_##i); i++)
#define FORL(i, a, b) FORT(ll, i, a, b)
#define FOR(i, a, b) FORT(int, i, a, b)
#define REPT(t, i, n) FORT(t, i, 0, n)
#define REPL(i, n) FORL(i, 0, n)
#define REP(i, n) FOR(i, 0, n)
#define EACH(i,c) for(auto i=(c).begin(); i!=(c).end(); ++i)
  
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define ALL(a) (a).begin(), (a).end()
#define SORT(a) sort(ALL(a))
#define SORTA(a, n) sort(a, a+n)
  
#define PB push_back
#define MP make_pair
#define itr iterator
  
// Range ///////////////////////////////////////////////////////////////////////
#define IN(x, a, b) (a<=x && x<b)
#define INC(x, a, b) (a<=x && x<=b)
int dx[8] = { 1, 0, 0,-1, 1, 1,-1,-1};
int dy[8] = { 0,-1, 1, 0,-1, 1,-1, 1};
  
#define LAR(a, b) ((a)=max((a), (b)))
#define SML(a, b) ((a)=min((a), (b)))
  
// Debug ///////////////////////////////////////////////////////////////////////
#define println(...) {printf(__VA_ARGS__); printf("\n");}
#ifdef LOCAL
#define debug(...) printf(__VA_ARGS__)
#define debugln(...) println(__VA_ARGS__)
#else
#define debug(...) {}
#define debugln(...) {}
#endif

// Numbers /////////////////////////////////////////////////////////////////////
ll gcd(ll a, ll b){
    if(b==0) return a;
    else return gcd(b, a%b);
}
  
#define PRIME_MAX 1000000
bool isprime[PRIME_MAX+5];
void init_prime(){
    fill(isprime, isprime+PRIME_MAX+5, true);
    isprime[0]=isprime[1]=false;
    REP(i, PRIME_MAX+5){
        if(isprime[i]){
            for(int j=i*2; j<PRIME_MAX; j+=i){
                isprime[j]=false;
            }
        }
    }
}
  
vll factors(ll n){
    vll v;
    REPL(i, PRIME_MAX){
        if(!isprime[i]) continue;
        while(n%i==0){
            v.PB(i);
            n/=i;
        }
    }
    if(n>1){
        v.PB(n);
    }
    return v;
}
  
// BIT /////////////////////////////////////////////////////////////////////////
template<
    typename T = int
>
class bit{
public:
    T *bit_arr;
    int size;
  
    bit(int n){
        size = n;
        bit_arr = new T[n];
        fill(bit_arr, bit_arr+n, 0);
    }
  
    ~bit(){
        delete bit_arr;
    }
  
    T sum(int a){
        T ret = 0;
        while(a){
            ret+=bit_arr[a];
            a-=a&-a;
        }
        return ret;
    }
  
    T sum(int a, int b){
        return sum(b)-sum(a);
    }
  
    T get(int a){
        return sum(a, a+1);
    }
  
    void add(int a, T x){
        a++;
        while(a<size){
            bit_arr[a]+=x;
            a+=a&-a;
        }
    }
  
    void set(int a, T x){
        add(a, x-get(a));
    }
};
typedef bit<ll> bll;
  
// RMQ /////////////////////////////////////////////////////////////////////////
template<
    typename T = int,
    class Compare=less<T>
>
class rmq{
public:
    int size;
    Compare comp;
    T *dat;
    T init;
     
    rmq(int n, T init_=INT_MAX){
        init=init_;
        size = 1;
        while(size<n) size*=2;
        dat = new T[2*size-1];
        fill(dat, dat+(2*size-1), init);
    }
  
    ~rmq(){
        delete dat;
    }
  
    void set(int k, T a){
        k+=size-1;
        dat[k]=a;
        while(k>0){
            k=(k-1)/2;
            dat[k]=min(dat[k*2+1], dat[k*2+2], comp);
        }
    }
  
    T get(int a, int b, int k, int l, int r){
        if(r<=a || b<=l) return init;
        if(a<=l && r<=b) return dat[k];
        else{
            T vl = get(a, b, k*2+1, l, (l+r)/2);
            T vr = get(a, b, k*2+2, (l+r)/2, r);
            return min(vl, vr, comp);
        }
    }
  
    T get(int a, int b){
        return get(a, b, 0, 0, size);
    }
};
  
// Others //////////////////////////////////////////////////////////////////////
#define MOD 1000000007
#define YES() printf("Yes\n")
#define NO() printf("No\n")
  
////////////////////////////////////////////////////////////////////////////////

int main(){
    ll a[90]={2,1};
    FOR(i,2,90)a[i]=a[i-2]+a[i-1];
    I(n);
    printf("%lld\n",a[n]);
}#include <bits/stdc++.h>
using namespace std;
  
// Macro Tools /////////////////////////////////////////////////////////////////
#define GET_MACRO_09(A0, A1, A2, A3, A4, A5, A6, A7, A8, NAME, ...) NAME
  
#define EXPAND_01(MACRO, A0, ...) \
    MACRO(A0, ##__VA_ARGS__) 
#define EXPAND_02(MACRO, A0, A1, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) 
#define EXPAND_03(MACRO, A0, A1, A2, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__) 
#define EXPAND_04(MACRO, A0, A1, A2, A3, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) 
#define EXPAND_05(MACRO, A0, A1, A2, A3, A4, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) MACRO(A4, ##__VA_ARGS__) 
#define EXPAND_06(MACRO, A0, A1, A2, A3, A4, A5, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) MACRO(A4, ##__VA_ARGS__) MACRO(A5, ##__VA_ARGS__) 
#define EXPAND_07(MACRO, A0, A1, A2, A3, A4, A5, A6, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) MACRO(A4, ##__VA_ARGS__) MACRO(A5, ##__VA_ARGS__)  \
    MACRO(A6, ##__VA_ARGS__) 
#define EXPAND_08(MACRO, A0, A1, A2, A3, A4, A5, A6, A7, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) MACRO(A4, ##__VA_ARGS__) MACRO(A5, ##__VA_ARGS__)  \
    MACRO(A6, ##__VA_ARGS__) MACRO(A7, ##__VA_ARGS__) 
#define EXPAND_09(MACRO, A0, A1, A2, A3, A4, A5, A6, A7, A8, ...) \
    MACRO(A0, ##__VA_ARGS__) MACRO(A1, ##__VA_ARGS__) MACRO(A2, ##__VA_ARGS__)  \
    MACRO(A3, ##__VA_ARGS__) MACRO(A4, ##__VA_ARGS__) MACRO(A5, ##__VA_ARGS__)  \
    MACRO(A6, ##__VA_ARGS__) MACRO(A7, ##__VA_ARGS__) MACRO(A8, ##__VA_ARGS__) 
  
#define GET_EXPAND(...) GET_MACRO_09(__VA_ARGS__, EXPAND_09, EXPAND_08, \
    EXPAND_07, EXPAND_06, EXPAND_05, EXPAND_04, EXPAND_03, EXPAND_02, EXPAND_01)
#define EXPAND_ARG_0(MACRO, ...) GET_EXPAND(__VA_ARGS__)(MACRO, __VA_ARGS__)
#define EXPAND_ARG_1(MACRO, A0, ...) GET_EXPAND(__VA_ARGS__)(MACRO, __VA_ARGS__, A0)
  
#define EXPAND(MACRO, ...) EXPAND_ARG_0(MACRO, __VA_ARGS__)
  
#define Q(x) #x
#define QUOTE(x) Q(x)

// Input ///////////////////////////////////////////////////////////////////////
#define SCANF_INT(a) scanf("%d", &(a));
#define ID(...) int __VA_ARGS__;
#define IR(...) {EXPAND(SCANF_INT, __VA_ARGS__)}
#define I(...) ID(__VA_ARGS__) IR(__VA_ARGS__)
  
// #define DEFINE_INT_ARRAY(a, n) int a[n];
// #define INT_ITH_ARRAY(a, i) a[i]
// #define IAD(N, ...) EXPAND_ARG_1(DEFINE_INT_ARRAY, N, __VA_ARGS__)
// #define IAR(N, ...) REP(array_reader_i, N){ 
  
#define SCANF_LL(a) scanf("%lld", &(a));
#define LD(...) ll __VA_ARGS__;
#define LR(...) {EXPAND(SCANF_LL, __VA_ARGS__)}
#define L(...) LD(__VA_ARGS__) LR(__VA_ARGS__)
  
#define SCANF_LD(a) scanf("%Lf", &(a));
#define DD(...) lD __VA_ARGS__;
#define DR(...) {EXPAND(SCANF_LD, __VA_ARGS__)}
#define D(...) DD(__VA_ARGS__) DR(__VA_ARGS__)
  
#define DEFINE_STR(a, n) char a[n];
#define SCANF_STR(a) scanf("%s", a);
#define SD(N, ...) EXPAND_ARG_1(DEFINE_STR, N, __VA_ARGS__)
#define SR(...) EXPAND(SCANF_STR, __VA_ARGS__)
#define S(N, ...) SD(N, __VA_ARGS__) SR(__VA_ARGS__)
  
// Output //////////////////////////////////////////////////////////////////////
#define LN printf("\n")
#define FL fflush(stdout)
  
#define IP(a, ...) printf("%d", a); 
  
// Types ///////////////////////////////////////////////////////////////////////
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<int, ll> pil;
typedef pair<ll, int> pli;
typedef pair<ll, ll> pll;
typedef set<int> si;
typedef set<ll> sll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef list<int> li;
typedef list<ll> lll;
typedef map<int, int> mii;
typedef map<int, ll> mil;
typedef map<ll, int> mli;
typedef map<ll, ll> mll;
  
// Loop & Iteration ////////////////////////////////////////////////////////////
#define FORT(t, i, a, b) \
    for(t i = (a), loop_end_##i=(b); i < (loop_end_##i); i++)
#define FORL(i, a, b) FORT(ll, i, a, b)
#define FOR(i, a, b) FORT(int, i, a, b)
#define REPT(t, i, n) FORT(t, i, 0, n)
#define REPL(i, n) FORL(i, 0, n)
#define REP(i, n) FOR(i, 0, n)
#define EACH(i,c) for(auto i=(c).begin(); i!=(c).end(); ++i)
  
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define ALL(a) (a).begin(), (a).end()
#define SORT(a) sort(ALL(a))
#define SORTA(a, n) sort(a, a+n)
  
#define PB push_back
#define MP make_pair
#define itr iterator
  
// Range ///////////////////////////////////////////////////////////////////////
#define IN(x, a, b) (a<=x && x<b)
#define INC(x, a, b) (a<=x && x<=b)
int dx[8] = { 1, 0, 0,-1, 1, 1,-1,-1};
int dy[8] = { 0,-1, 1, 0,-1, 1,-1, 1};
  
#define LAR(a, b) ((a)=max((a), (b)))
#define SML(a, b) ((a)=min((a), (b)))
  
// Debug ///////////////////////////////////////////////////////////////////////
#define println(...) {printf(__VA_ARGS__); printf("\n");}
#ifdef LOCAL
#define debug(...) printf(__VA_ARGS__)
#define debugln(...) println(__VA_ARGS__)
#else
#define debug(...) {}
#define debugln(...) {}
#endif

// Numbers /////////////////////////////////////////////////////////////////////
ll gcd(ll a, ll b){
    if(b==0) return a;
    else return gcd(b, a%b);
}
  
#define PRIME_MAX 1000000
bool isprime[PRIME_MAX+5];
void init_prime(){
    fill(isprime, isprime+PRIME_MAX+5, true);
    isprime[0]=isprime[1]=false;
    REP(i, PRIME_MAX+5){
        if(isprime[i]){
            for(int j=i*2; j<PRIME_MAX; j+=i){
                isprime[j]=false;
            }
        }
    }
}
  
vll factors(ll n){
    vll v;
    REPL(i, PRIME_MAX){
        if(!isprime[i]) continue;
        while(n%i==0){
            v.PB(i);
            n/=i;
        }
    }
    if(n>1){
        v.PB(n);
    }
    return v;
}
  
// BIT /////////////////////////////////////////////////////////////////////////
template<
    typename T = int
>
class bit{
public:
    T *bit_arr;
    int size;
  
    bit(int n){
        size = n;
        bit_arr = new T[n];
        fill(bit_arr, bit_arr+n, 0);
    }
  
    ~bit(){
        delete bit_arr;
    }
  
    T sum(int a){
        T ret = 0;
        while(a){
            ret+=bit_arr[a];
            a-=a&-a;
        }
        return ret;
    }
  
    T sum(int a, int b){
        return sum(b)-sum(a);
    }
  
    T get(int a){
        return sum(a, a+1);
    }
  
    void add(int a, T x){
        a++;
        while(a<size){
            bit_arr[a]+=x;
            a+=a&-a;
        }
    }
  
    void set(int a, T x){
        add(a, x-get(a));
    }
};
typedef bit<ll> bll;
  
// RMQ /////////////////////////////////////////////////////////////////////////
template<
    typename T = int,
    class Compare=less<T>
>
class rmq{
public:
    int size;
    Compare comp;
    T *dat;
    T init;
     
    rmq(int n, T init_=INT_MAX){
        init=init_;
        size = 1;
        while(size<n) size*=2;
        dat = new T[2*size-1];
        fill(dat, dat+(2*size-1), init);
    }
  
    ~rmq(){
        delete dat;
    }
  
    void set(int k, T a){
        k+=size-1;
        dat[k]=a;
        while(k>0){
            k=(k-1)/2;
            dat[k]=min(dat[k*2+1], dat[k*2+2], comp);
        }
    }
  
    T get(int a, int b, int k, int l, int r){
        if(r<=a || b<=l) return init;
        if(a<=l && r<=b) return dat[k];
        else{
            T vl = get(a, b, k*2+1, l, (l+r)/2);
            T vr = get(a, b, k*2+2, (l+r)/2, r);
            return min(vl, vr, comp);
        }
    }
  
    T get(int a, int b){
        return get(a, b, 0, 0, size);
    }
};
  
// Others //////////////////////////////////////////////////////////////////////
#define MOD 1000000007
#define YES() printf("Yes\n")
#define NO() printf("No\n")
  
////////////////////////////////////////////////////////////////////////////////

int main(){
    ll a[90]={2,1};
    FOR(i,2,90)a[i]=a[i-2]+a[i-1];
    I(n);
    printf("%lld\n",a[n]);
}

Compiler output:
a.cc:280:2: error: stray '#' in program
  280 | }#include <bits/stdc++.h>
      |  ^
a.cc:280:3: error: 'include' does not name a type
  280 | }#include <bits/stdc++.h>
      |   ^~~~~~~
a.cc:398:5: error: redefinition of 'int dx [8]'
  398 | int dx[8] = { 1, 0, 0,-1, 1, 1,-1,-1};
      |     ^~
a.cc:119:5: note: 'int dx [8]' previously defined here
  119 | int dx[8] = { 1, 0, 0,-1, 1, 1,-1,-1};
      |     ^~
a.cc:399:5: error: redefinition of 'int dy [8]'
  399 | int dy[8] = { 0,-1, 1, 0,-1, 1,-1, 1};
      |     ^~
a.cc:120:5: note: 'int dy [8]' previously defined here
  120 | int dy[8] = { 0,-1, 1, 0,-1, 1,-1, 1};
      |     ^~
a.cc:415:4: error: redefinition of 'll gcd(ll, ll)'
  415 | ll gcd(ll a, ll b){
      |    ^~~
a.cc:136:4: note: 'll gcd(ll, ll)' previously defined here
  136 | ll gcd(ll a, ll b){
      |    ^~~
a.cc:421:6: error: redefinition of 'bool isprime [1000005]'
  421 | bool isprime[PRIME_MAX+5];
      |      ^~~~~~~
a.cc:142:6: note: 'bool isprime [1000005]' previously declared here
  142 | bool isprime[PRIME_MAX+5];
      |      ^~~~~~~
a.cc:422:6: error: redefinition of 'void init_prime()'
  422 | void init_prime(){
      |      ^~~~~~~~~~
a.cc:143:6: note: 'void init_prime()' previously defined here
  143 | void init_prime(){
      |      ^~~~~~~~~~
a.cc:434:5: error: redefinition of 'vll factors(ll)'
  434 | vll factors(ll n){
      |     ^~~~~~~
a.cc:155:5: note: 'vll factors(ll)' previously defined here
  155 | vll factors(ll n){
      |     ^~~~~~~
a.cc:451:5: error: redefinition of default argument for 'class T'
  451 |     typename T = int
      |     ^~~~~~~~
a.cc:172:5: note: original definition appeared here
  172 |     typename T = int
      |     ^~~~~~~~
a.cc:501:5: error: redefinition of default argument for 'class T'
  501 |     typename T = int,
      |     ^~~~~~~~
a.cc:222:5: note: original definition appeared here
  222 |     typename T = int,
      |     ^~~~~~~~
a.cc:554:5: error: redefinition of 'int main()'
  554 | int main(){
      |     ^~~~
a.cc:275:5: note: 'int main()' previously defined here
  275 | int main(){
      |     ^~~~