#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>

char *tab;

int ft_weird_atoi(void)
{
    int ret= 0, sign = 1;
    if (*tab == '-')
    {
        sign = -1;
        ++tab;
    }
    while (*tab != '\n')
        ret = ret * 10 + *tab++ - '0';
    ++tab;
    return ret * sign;
}

int main()
{
    struct stat s_stat;
    fstat(0, &s_stat);

    tab = (char *)mmap(0, s_stat.st_size, PROT_READ, MAP_SHARED, STDIN_FILENO, 0);
    int summ = 0;
    char *fin = tab + s_stat.st_size;
    ft_weird_atoi();
    while (tab != fin)
        summ += ft_weird_atoi();
    printf("%d\n", summ);
}