#include using namespace std; #define INF_LL (int64)1e18 #define INF (int32)1e9 #define REP(i, n) for(int64 i = 0;i < (n);i++) #define FOR(i, a, b) for(int64 i = (a);i < (b);i++) #define all(x) x.begin(),x.end() #define fs first #define sc second using int32 = int_fast32_t; using uint32 = uint_fast32_t; using int64 = int_fast64_t; using uint64 = uint_fast64_t; using PII = pair; using PLL = pair; const double eps = 1e-10; templateinline void chmin(A &a, B b){if(a > b) a = b;} templateinline void chmax(A &a, B b){if(a < b) a = b;} template vector make_v(size_t a){return vector(a);} template auto make_v(size_t a,Ts... ts){ return vector(ts...))>(a,make_v(ts...)); } template typename enable_if::value!=0>::type fill_v(U &u,const V... v){u=U(v...);} template typename enable_if::value==0>::type fill_v(U &u,const V... v){ for(auto &e:u) fill_v(e,v...); } int main(void) { cin.tie(0); ios::sync_with_stdio(false); int64 A, B, C; cin >> A >> B >> C; cout << min({max((int64)0, B-max(A, C)), abs(A-C)}) << endl; }