#pragma comment(linker, "/STACK:1024000000,1024000000")

#include <cstdio>

#include <string>

#include <cstdlib>

#include <cmath>

#include <iostream>

#include <cstring>

#include <set>

#include <queue>

#include <algorithm>

#include <vector>

#include <map>

#include <cctype>

#include <cmath>

#include <stack>

#define freopenr freopen("in.txt", "r", stdin)

#define freopenw freopen("out.txt", "w", stdout)

using namespace std;

typedef long long LL;

typedef pair<int, int> P;

const int INF = 0x3f3f3f3f;

const double inf = 0x3f3f3f3f3f3f;

const double PI = acos(-1.0);

const double eps = 1e-8;

const int maxn = 1e5 + 5;

const int mod = 1e9 + 7;

const int dr[] = {-1, 0, 1, 0};

const int dc[] = {0, 1, 0, -1};

const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};

int n, m;

const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

inline int Min(int a, int b){ return a < b ? a : b; }

inline int Max(int a, int b){ return a > b ? a : b; }

inline LL Min(LL a, LL b){ return a < b ? a : b; }

inline LL Max(LL a, LL b){ return a > b ? a : b; }

inline bool is_in(int r, int c){

    return r >= 0 && r < n && c >= 0 && c < m;

}

LL dp[15][15];

int a[15];

LL dfs(int pos, int num, bool is, bool ok){

    if(!pos)  return is ? 1 : num;

    LL &ans = dp[pos][num];

    if(!ok && ans >= 0 && !is)  return ans;

    LL res = 0;

    int n = ok ? a[pos] : 9;

    for(int i = 0; i <= n; ++i){

        if(is)  res += dfs(pos-1, num, !i, ok && i == n);

        else if(!i)  res += dfs(pos-1, num+1, false, ok && i == n);

        else res += dfs(pos-1, num, false, ok && i == n);

    }

    if(!ok && !is)  ans = res;

    return res;

}

LL solve(LL n){

    if(n == -1)  return 0;

    int len = 0;

    while(n > 0){

        a[++len] = n % 10;

        n /= 10;

    }

    return dfs(len, 0, true, true);

}

int main(){

    memset(dp, -1, sizeof dp);

    LL x, y;

    int T;  cin >> T;

    for(int kase = 1; kase <= T; ++kase){

        scanf("%lld %lld", &x, &y);

        printf("Case %d: %lld\n", kase, solve(y)-solve(x-1));

    }

    return 0;

}