N = input().strip()
ans = 0
for a1 in range(1,10):
    a1 = str(a1)
    M = a1+a1+"0"*7+a1+a1
    if len(M)<len(N):
        ans += 1
    elif len(M)==len(N) and M<=N:
        ans += 1
    M = a1+"0"*8+a1
    if len(M)<len(N):
        ans += 1
    elif len(M)==len(N) and M<=N:
        ans += 1
    for a2 in range(10):
        a2 = str(a2)
        M = a1+a2+a2+a1
        M = M+"0"*5+M
        if len(M)<len(N):
            ans += 1
        elif len(M)==len(N) and M<=N:
            ans += 1
        M = a1+a2+a1
        M = M+"0"*6+M
        if len(M)<len(N):
            ans += 1
        elif len(M)==len(N) and M<=N:
            ans += 1
        for a3 in range(10):
            a3 = str(a3)
            M = a1+a2+a3+a3+a2+a1
            M = M+"0"*3+M
            if len(M)<len(N):
                ans += 1
            elif len(M)==len(N) and M<=N:
                ans += 1
            M = a1+a2+a3+a2+a1
            M = M+"0"*4+M
            if len(M)<len(N):
                ans += 1
            elif len(M)==len(N) and M<=N:
                ans += 1
            for a4 in range(10):
                a4 = str(a4)
                M = a1+a2+a3+a4+a4+a3+a2+a1
                M = M+"0"+M
                if len(M)<len(N):
                    ans += 1
                elif len(M)==len(N) and M<=N:
                    ans += 1
                M = a1+a2+a3+a4+a3+a2+a1
                M = M+"00"+M
                if len(M)<len(N):
                    ans += 1
                elif len(M)==len(N) and M<=N:
                    ans += 1
                for a5 in range(10):
                    a5 = str(a5)
                    M = a1+a2+a3+a4+a5+a4+a3+a2+a1
                    M = M+M
                    if len(M)<len(N):
                        ans += 1
                    elif len(M)==len(N) and M<=N:
                        ans += 1
print(ans)