https://codeforces.com/contest/991
A
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define lson l,mid,rt<<1 4 #define rson mid+1,r,rt<<1|1 5 #define IT set<ll>::iterator 6 #define sqr(x) ((x)*(x)) 7 #define pb push_back 8 #define eb emplace_back 9 #define maxn 1000006 10 #define eps 1e-8 11 #define pi acos(-1.0) 12 #define rep(k,i,j) for(int k=i;k<j;k++) 13 typedef long long ll; 14 typedef pair<int,int> pii; 15 typedef pair<ll,ll>pll; 16 typedef pair<ll,int> pli; 17 typedef pair<pair<int,string>,pii> ppp; 18 typedef unsigned long long ull; 19 const long long MOD=998244353; 20 const double oula=0.57721566490153286060651209; 21 using namespace std; 22 23 24 int main(){ 25 std::ios::sync_with_stdio(false); 26 int a,b,c,n; 27 cin>>a>>b>>c>>n; 28 int ans=n-a-b+c; 29 if(ans>0&&a<n&&b<n&&c<n&&n-ans>=a&&n-ans>=b&&n-ans>=c&&c<=a&&c<=b&&ans<=n) cout<<ans<<endl; 30 else cout<<-1<<endl; 31 }