// #include <bits/stdc++.h>
#include <iostream>
#include <cmath>
#include <string>
#include <algorithm>
#include <functional>
#include <vector>
#include <stack>
#include <queue>
#include <map>
// #include <unordered_map>
#include <set>
// #include <unordered_set>

#define debug(var)  do{std::cout << #var << " :";std::cout << std::endl;view(var);}while(0)
template<typename T> void view(T e){ std::cout << e << std::endl;}
template<typename T> void view(const std::vector<T>& v){ int c = v.size(); std::cout << "{"; for(const auto& e : v){ std::cout << e; if (--c) std::cout << ", "; } std::cout << "}" << std::endl; }
template<typename T, typename U> void view(const std::pair<T, U>& v){ std::cout << v.first << ", " << v.second << std::endl; }
template<typename T> void view(const std::set<T>& v){ int c = v.size(); std::cout << "{"; for(const auto& e : v){ std::cout << e; if (--c) std::cout << ", "; } std::cout << "}" << std::endl; }
template<typename T, typename U> void view(const std::map<T, U>& v){ std::cout << "{" << std::endl; for(const std::pair<T, U>& e : v){ std::cout << e.first << ", " << e.second << std::endl; } std::cout << "}" << std::endl; }
template<typename T> void view(const std::vector<std::vector<T> >& vv){ std::cout << "{" << std::endl; for(const auto& v : vv){ view(v); } std::cout << "}" << std::endl; }

using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
typedef long long ll;
typedef pair<int, int> pii;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const long long INF = 1LL << 60;
const long long MOD = 1000000007;
// const double PI = acos(-1);

int main() {
    vector<int> A(3);
    rep(i, 3) cin >> A[i];

    sort(A.begin(), A.end());

    if (A[0] == A[1]) {
        cout << A[2] << endl;
    } else if (A[1] == A[2]) {
        cout << A[0] << endl;
    } else {
        cout << 0 << endl;
    }
}
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("fast-math")

#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#define deb(x) cout << #x << " is " << x << "\n"
#define int long long
#define MOD 1000000007LL
#define PI acos(-1)

template <typename T>
using min_heap = priority_queue<T, vector<T>, greater<T>>;

template <typename T>
using max_heap = priority_queue<T>;

template <class T>
using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

template <typename... T>
void read(T &...args) {
    ((cin >> args), ...);
}

template <typename... T>
void write(T &&...args) {
    ((cout << args), ...);
}

template <typename T>
void readContainer(T &t) {
    for (auto &e : t) {
        read(e);
    }
}

template <typename T>
void writeContainer(T &t) {
    for (const auto &e : t) {
        write(e, " ");
    }
    write("\n");
}

auto speedup = []() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    return nullptr;
}();

void solve(int tc) {
    long double A, B;
    read(A, B);
    long double ans = ((A - B) / A) * 100.0;
    cout << fixed << setprecision(16) << ans << "\n";
}

signed main() {
    int tc = 1;
    // read(tc);
    for (int curr = 1; curr <= tc; ++curr) {
        solve(curr);
    }
    return 0;
}