试一下__int128_t

#include <iostream>
#include <cstdio>
using namespace std;
__int128_t read(){
    char c = getchar();
    __int128_t x = 0;
    while(!isdigit(c)) c = getchar();
    while(isdigit(c)){
        x = (x << 3) + (x << 1) + c - '0';
        c = getchar();
    }return x;
}
void cout_128(__int128_t n){
    string s;
    while(n){
        s = char(n % 10 + '0') + s;
        n /= 10;
    }cout << s;
}
int main(){
    __int128_t n = read(), m = read();
    cout_128(n + m);
}