#include <stdio.h>
#include <string.h>

#define NMAX 4000

int n, a[NMAX], c[NMAX];

char s[NMAX];


void inmultire(int a[])
{
    int i, j, t;
    for ( i = 1; i <= a[0]; i++)
    {
        for ( t = 0, j = 1; j <= a[0] || t; j++, t /= 10)
            c[ i + j - 1] = ( t += c[i + j - 1] + a[i] * a[j]) % 10;
        if ( i + j - 2 > c[0])
            c[0] = i + j - 2;
    }

}

void scade(int c[], int a[])
{
    int i, t = 0;

    for ( i = 1; i <= c[0]; i++)
        c[i] += ( t = (c[i] -= a[i] + t) < 0) * 10;

    for ( ; c[0] > 1 &&  c[c[0]] == 0;  c[0]--);
}


void aduna(int c[], int x)
{
    int i, t = 0;

    c[1] += x;
    t = c[1] / 10;
    c[1] = c[1] % 10;
    for ( i = 2; i <= c[0] || t; i++, t /= 10)
        c[i] = ( t += c[i] ) % 10;

   c[0] = i - 1;
}

void inmulti(int c[], int x)
{
    int i, t = 0;
    for (i = 1; i <= c[0] || t; i++, t /= 10)
        c[i] = ( t += c[i] * x ) % 10;
    c[0] = i - 1;
}

int main()
{
    int i;

    freopen("sarpe.in", "r", stdin);
    freopen("sarpe.out", "w", stdout);
    scanf("%s", s);
    n = strlen(s);
    for ( i = n - 1; i >= 0; i--)
        a[++a[0]] = s[i] - '0';
    if (a[0] == 1 && a[a[0]] == 1)
        printf("2\n");
    else
    {

        inmultire(a);
        scade(c, a);
        aduna(c, 2);
        inmulti(c, 2);

        for ( i = c[0]; i >= 1; i--)
            printf("%d", c[i]);
        printf("\n");
    }

    return 0;
}