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#include <iostream>
#include <vector>
#include <cmath>
using namespace std;
long get(long count, int l) {
vector<long> list;
long n = count;
while (n % 2 == 0) {
list.push_back(2);
n /= 2;
}
for (long i = 3; i <= sqrt(n); i += 2) {
while (n % i == 0) {
list.push_back(i);
n /= i;
}
}
if (n > 2) {
list.push_back(n);
}
if (list.size() == 1) {
return count;//是质数
} else {
for (long aLong : list) {
if (count / aLong < l) {
return count;//最大的因数小于l,那他不可能是l到r之间的数的倍数
} else {
break;
}
}
}
return -1;
}
int main() {
int n, l, r;
cin >> n >> l >> r;
if (n < l) {
cout << 0 << endl;
return 0;
}
if (n == l) {
cout << 1 << endl;
return 0;
}
long res = 0, count = max(n, r + 1);
while (true) {
long l1 = get(count, l);
if (l1 != -1) {//count是质数或满足条件
res = count - n;//到n的距离
break;
}
count++;
}
count = n - 1;
while (count > r) {//如果n大于r,判断r到n之间的数
long l1 = get(count, l);
if (l1 != -1) {
res = min(n - count, res);
break;
}
count--;
}
cout << min(res, static_cast<long>(n - l + 1)) << endl;
return 0;
}