我靠，getchar被卡了！

#include <iostream>

class cin {
public:
    cin operator>>(int &num) {
        num = 0;
        int f = 1;
        char c = getchar();
        while (c < '0' || c > '9') {
            if (c == '-') f = -1;
            c = getchar();
        }
        while (c >= '0' && c <= '9') {
            num = num * 10 + (c - '0');
            c = getchar();
        }
        num *= f;
        return *this;
    }
} cin;

class cout {
public:
    cout operator<<(long long num) {
        if (num < 0) {
            putchar('-');
            num = -num;
        }
        if (num >= 10) (*this) << (num / 10);
        putchar(num % 10 + '0');
        return *this;
    }
} cout;


int n{}, a{};
long long sum{};


signed main() {
    cin >> n;
    while (n--) {
        cin >> a;
        sum += a;
    }
    cout << sum;
}