#include<cstdio>
#include<cstring>
char a[210],b[210],c[210];
short n,i,t,d,e,f;
int main() {
    freopen("nunta.in","r",stdin),freopen("nunta.out","w",stdout),scanf("%hd",&n),d=e=f=1,a[1]=b[1]=c[1]='1';
    for(;n>1;n--) {
        for(t=0,i=1;i<=d||i<=e||t;i++,t/=10)
            c[i]=(t+=(a[i]-'0')+(b[i]-'0'))%10+'0';
        f=i-1,memcpy(a,b,e),memcpy(b,c,f);
    }
    for(i=f;i;i--)
        printf("%hd",c[i]-'0');
}