#include <bits/stdc++.h>
using namespace std;
int n, a, b;
bitset<1000010> st[110];
int main(int argc, char const *argv[]) {
cin >> n; st[0][0] = 1;
for (int i = 1; i <= n; i++) {
scanf("%d%d", &a, &b);
for (int j = a; j <= b; j++)
st[i] |= st[i - 1] << (j * j);
}
cout << st[n].count() << endl;
}