By @ZYLZPP

已模块化，选择需要的函数

使用方式与 cin/cout 相同

#include<bits/stdc++.h>
using namespace std;

#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
#define rFor(i, r, l) for (int i = (r); i >= (l); --i)
#define For(i, l, r) for (int i = (l); i <= (r); ++i)
typedef long long ll;
typedef double lf;
const int N = 5e5 + 5, Mo = 1e9 + 9;
inline int mo(int x) { return x -= x>=Mo? Mo: x<0? -Mo: 0; }
inline void add(int &x, const int &y) { x = mo(x + y); }
inline int ml(const int &x, const int &y) { return 1ll * x * y % Mo; }
inline void mul(int &x, const int &y) { x = ml(x, y); }
inline int qPow(int a, int b) { int r=1; for (;b;b>>=1,mul(a,a)) if (b&1) mul(r,a); return r; }
template<class C> inline bool cmax(C &x, const C &y) { return y>x? x=y, 1: 0; }
template<class C> inline bool cmin(C &x, const C &y) { return y<x? x=y, 1: 0; }

struct IO {
    //input
    char c; int f;
#define gc() getchar()
    template<class C>
    inline IO& operator >> (C &x) {
        x = 0; f = 1;
        while (!isdigit(c = gc()) && ~c) f |= -!(c ^ 45);
        while (isdigit(c)) x = (x << 3) + (x << 1) + (c ^ 48), c = gc();
        x *= f; return *this;
    }//整型
    inline IO& operator >> (char &x) {
        while ((c = gc()) < 33 && ~c);
        x = c; return *this;
    }//字符
    inline IO& operator >> (char *x) {
        while ((c = gc()) < 33 && ~c);
        while (c > 32) *x++ = c, c = gc();
        *x = 0; return *this;
    }//字符串
    inline IO& operator >> (double &x) {
        double p(1); x = 0; f = 1;
        while (!isdigit(c = gc()) && ~c) f |= -!(c ^ 45);
        while (isdigit(c)) x = x * 10 + (c ^ 48), c = gc();
        if (!(c ^ 46)) while (isdigit(c = gc())) x += (c ^ 48) * (p /= 10);
        x *= f; return *this;
    }//double

    //output
    int st[66], t;
#define pc(c) putchar(c)
    template<class C>
    inline IO& operator << (C x) {
        if (!x) pc('0'); if (x < 0) pc('-'), x = -x;
        while (x) st[++t] = x % 10, x /= 10;
        while (t) pc(st[t--] ^ 48);
        return *this;
    }//整型
    inline IO& operator << (char x) {
        pc(x); return *this;
    }//字符
    template<class C>
    inline IO& operator << (C *x) {
        while (*x) pc(*x++);
        return *this;
    }//字符串
    inline bool operator ~ () const { return ~c; } //判断是否文件未结束 文件结束时c==EOF==-1
} io;

int main() {
    char a[45];
    scanf("%s", a);
    io << a;
    io << "123";
    return 0;
}
//2024.8.10_