include<bits/stdc++.h>

using namespace std;

int main(){

long long n,l,r;
cin>>n>>l>>r;
vector<long long> s;
for(long long i=l;i<=r;i++){
	s.push_back(i%n);
}
long long s1=*max_element(s.begin(),s.end());
cout<<s1;
return 0;

}