#include <cstring>
#include <cstdio>

#define BASE 100

using namespace std;

char v1[105] , v2[105] , v3[105];
short int n;

void adun(char A[] , char B[] , char C[]);
void copie(char A[] , char B[]);
void afis(char A[]);

int main() {
    freopen("nunta.in" , "r" , stdin);
    freopen("nunta.out" , "w" , stdout);
    scanf("%hd" , &n);

    v1[1] = v1[0] = 1;
    v2[1] = v2[0] = 1;
    v3[1] = v3[0] = 1;

    for (short int i = 2; i <= n; ++i) {
        adun(v3 , v2 , v1);
        copie(v1 , v2);
        copie(v2 , v3);
    }

    afis(v3);
}

void adun(char A[] , char B[] , char C[]) {
    short int t = 0;

    memset(A , 0 , sizeof(A));
    A[0] = B[0];

    for (short int i = 1; i <= B[0]; ++i) {
        short int aux = B[i] + C[i] + t;
        t = aux / BASE;
        A[i] = aux % BASE;
    }

    while (t) {
        A[++A[0]] = t % BASE;
        t /= BASE;
    }
}

void copie(char A[] , char B[]) {
    memset(A , 0 , sizeof(A));
    for (short int i = 0; i <= B[0]; ++i) {
        A[i] = B[i];
    }
}


void afis(char A[]) {
    printf("%d", A[A[0]]);
    for (short int  i = A[0] - 1; i > 0; --i) {
        short int x = (short int)A[i] , nr = 0;
        if (x == 0)
            nr = 1;

        while (x) {
            ++nr;
            x /= 10;
        }

        for(short int j = nr + 1; j <= 2; ++j) {
            printf("0");
        }

        printf("%d", (int)A[i]);
    }
}