Misha and Vanya have played several table tennis sets. Each set consists of several serves, each serve is won by one of the players, he receives one point and the loser receives nothing. Once one of the players scores exactly *k* points, the score is reset and a new set begins.

Across all the sets Misha scored *a* points in total, and Vanya scored *b* points. Given this information, determine the maximum number of sets they could have played, or that the situation is impossible.

Note that the game consisted of several complete sets.
The first line contains three space-separated integers *k*, *a* and *b* (1 ≤ *k* ≤ 10<sup class="upper-index">9</sup>, 0 ≤ *a*, *b* ≤ 10<sup class="upper-index">9</sup>, *a* + *b* &gt; 0).
Note that the rules of the game in this problem differ from the real table tennis game, for example, the rule of "balance" (the winning player has to be at least two points ahead to win a set) has no power within the present problem.
11 11 5
1
11 2 3
-1
1 5 9
14
2 3 3
2
1 1000000000 1000000000
2000000000
2 3 5
3
1000000000 1000000000 1000000000
2
1 0 1
1
101 99 97
-1
1000000000 0 1
-1
137 137 136
1
255 255 255
2
1 0 1000000000
1000000000
123 456 789
9
666666 6666666 666665
-1
1000000000 999999999 999999999
-1
100000000 100000001 99999999
-1
3 2 1000000000
-1
999999999 1000000000 999999998
-1
12938621 192872393 102739134
21
666666666 1230983 666666666
1
123456789 123456789 123456787
1
5 6 0
-1
11 0 12
-1
2 11 0
-1
2 1 0
-1
10 11 12
2
11 12 5
-1
11 12 3
-1
11 15 4
-1
2 3 1
-1
11 12 0
-1
11 13 2
-1
11 23 22
4
10 21 0
-1
11 23 1
-1
11 10 12
-1
11 1 12
-1
11 5 12
-1
11 8 12
-1
11 12 1
-1
5 4 6
-1
10 1 22
-1
2 3 0
-1
11 23 2
-1
2 1000000000 1000000000
1000000000
11 0 15
-1
11 5 0
-1
11 5 15
-1
10 0 13
-1
4 7 0
-1
10 2 8
-1
11 5 22
2
11 13 0
-1
2 0 3
-1
10 10 0
1
10 11 10
2
3 5 4
2
11 22 3
2
11 12 10
-1
10 2 13
-1
5 6 1
-1
10 21 5
-1
10 11 9
-1
10 17 7
-1
3 4 1
-1
4 5 3
-1
11 3 23
-1
11 3 12
-1
2 5 0
-1
10 21 2
-1
5 1 6
-1
10 11 0
-1
10 9 11
-1
7 10 5
-1
5 7 2
-1
6 5 7
-1
11 16 2
-1
11 1000000000 10
-1
10 2 21
-1
10 15 1
-1
5 2 8
-1
11 10000000 10
-1
10 1 101
-1
20 24 2
-1
11 24 0
-1
11 17 4
-1
11 13 1
-1
10 11 2
-1
11 23 3
-1
10 99 0
-1
6 7 4
-1
11 1 22
2
11 2 13
-1
2 1 3
-1
11 6 18
-1
11 122 4
-1
11 21 10
-1
3 2 4
-1
9 11 2
-1
11 0 7
-1
5 9 4
-1
100 105 5
-1
11 15 0
-1
5 6 4
-1
3 4 2
-1
2 9 0
-1
11 13 11
2
11 15 5
-1
11 4 15
-1
10 1 0
-1
11 16 8
-1
10 43 0
-1
11 13 5
-1
11 22 0
2
5 6 3
-1
2 1 11
-1
4 5 1
-1
11 23 0
-1
11 4 12
-1
12 13 1
-1
10 19 9
-1
3 7 2
-1
12 18 0
-1
11 25 3
-1
11 23 5
-1
2 1 5
-1
2 0 5
-1
11 24 1
-1
10 11 4
-1
2 0 1
-1
10 0 21
-1
3 0 7
-1
18 11 21
-1
3 7 0
-1
5 11 0
-1
11 5 13
-1
11 9 34
-1
11 13 9
-1
10 0 22
-1
5 1 12
-1
11 2 12
-1
11 9 12
-1
11 24 2
-1
11 23 6
-1
11 20 4
-1
2 5 1
-1
120 132 133
2
11 111 4
-1
10 7 11
-1
6 13 0
-1
5 11 1
-1
11 5 27
-1
11 15 3
-1
11 0 13
-1
11 13 10
-1
11 25 5
-1
4 3 5
-1
100 199 100
2
11 2 22
2
10 20 2
2
5 5 0
1
10 11 1
-1
11 12 2
-1
5 16 3
-1
12 14 1
-1
10 22 2
-1
2 4 0
2
11 34 7
-1
6 13 1
-1
11 0 23
-1
20 21 19
-1
11 33 22
5
10 4 41
-1
3 4 0
-1
11 15 7
-1
5 0 6
-1
11 3 22
2
2 6 0
3
10 11 11
2
11 33 0
3
4 6 2
-1
11 76 2
-1
7 9 4
-1
10 43 1
-1
22 25 5
-1
3 5 2
-1
11 1 24
-1
12 25 3
-1
11 0 22
2
4 2 5
-1
11 13 3
-1
11 12 9
-1
11 35 1
-1
5 3 6
-1
5 11 4
-1
12 8 14
-1
10 12 9
-1
11 12 13
2
11 15 2
-1
11 23 4
-1
5 3 11
-1
6 13 2
-1
4 1 0
-1
11 32 10
-1
2 11 1
-1
10 11 7
-1
11 26 0
-1
100 205 5
-1
4 0 2
-1
10 11 8
-1
11 22 5
2
4 0 5
-1
11 87 22
9
4 8 0
2
9 8 17
-1
10 20 0
2
10 9 19
-1
12 2 13
-1
11 24 5
-1
10 1 11
-1
4 0 9
-1
3 0 1
-1
11 12 4
-1
3 8 2
-1
11 17 10
-1
6 1 13
-1
11 25 0
-1
12 0 13
-1
10 5 20
2
11 89 2
-1
2 4 1
2
10 31 0
-1
11 34 1
-1
999 6693 8331
14
10 55 1
-1
11 12 8
-1
1 9 22
31
7572 9186 895
-1
3 2 11
-1
2 1 4
2
11 10 19
-1
100 199 99
-1
2537 8926 1523
-1
11 0 5
-1
5 1 11
-1
12 13 5
-1
10 12 0
-1
5 4 7
-1
12 25 1
-1
7 9 0
-1
4 15 0
-1
5 11 2
-1
11 58 3
-1
10 11 5
-1
10 3 1003
-1
11 14 0
-1
11 8 23
-1
11 22 4
2
5 2 0
-1
11 1 35
-1
12 25 5
-1
11 37 4
-1
20 42 3
-1
10 12 2
-1
4 1 5
-1
5 16 0
-1
11 13 7
-1
5 0 3
-1
11 2 11
1
3 2 2000
-1
3 0 4241
-1
2 12 11
11
10 2 82
-1
11 0 11
1
11 20 20
2
5 0 10
2
11 1 0
-1
11 13 13
2
k, a, b = list(map(int, input().split()))
count = 0
if a + b < k:
    print(-1)
else:
    count1 = a // k
    count2 = b // k
    print(count1 + count2)
