#include <stdint.h>
#include <stdio.h>

#define LOOP_COUNT 1000000
#define EXPECTED_CHECKSUM 5000001

static int32_t math_loop(int32_t limit) {
    int32_t i = 0;
    int32_t acc = 1;

    while (i < limit) {
        acc = acc + ((i + 3) * 2);
        acc = acc > 1000000000 ? acc - 1000000000 : acc;
        i = i + 1;
    }

    return acc;
}

static int32_t configured_loop_count(void) {
    int32_t value = LOOP_COUNT;
    if (scanf("%d", &value) != 1 || value <= 0) {
        return LOOP_COUNT;
    }
    return value;
}

int main(void) {
    int32_t result = math_loop(configured_loop_count());
    printf("%d\n", result);
    return result == EXPECTED_CHECKSUM ? 0 : 1;
}
