import sys, os, io
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline
a, b, c, n = map(int, input().split())
if min(a, b) < c:
ans = -1
else:
x = n - (a + b - c)
ans = x if x > 0 else -1
print(ans)1920. Build Array from Permutation | 494. Target Sum |
797. All Paths From Source to Target | 1547B - Alphabetical Strings |
1550A - Find The Array | 118B - Present from Lena |
27A - Next Test | 785. Is Graph Bipartite |
90. Subsets II | 1560A - Dislike of Threes |
36. Valid Sudoku | 557. Reverse Words in a String III |
566. Reshape the Matrix | 167. Two Sum II - Input array is sorted |
387. First Unique Character in a String | 383. Ransom Note |
242. Valid Anagram | 141. Linked List Cycle |
21. Merge Two Sorted Lists | 203. Remove Linked List Elements |
733. Flood Fill | 206. Reverse Linked List |
83. Remove Duplicates from Sorted List | 116. Populating Next Right Pointers in Each Node |
145. Binary Tree Postorder Traversal | 94. Binary Tree Inorder Traversal |
101. Symmetric Tree | 77. Combinations |
46. Permutations | 226. Invert Binary Tree |