#include<cstdio>
int cifre(int n, int k){
    while(n!=0&&n%10!=k)
        n/=10;
    return n;
}
int main(){
    int i,nr,n,k=3;
    freopen("aparitii.in","r",stdin);
    freopen("aparitii.out","w",stdout);
    n=99;
    for(i=1,nr=0;i<=n;i++)
        if (cifre(i,k)!=0)
            nr++;
    printf("%d",nr);
    return 0;
}