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39 lines
906 B
C++

#define _CRT_SECURE_NO_WARNINGS
#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
#include <bits/stdc++.h>
using namespace std;
#define CRP(t, x) const t &x
#define OPL(t, x) bool operator<(CRP(t, x)) const
#define FIL(x, v) memset(x, v, sizeof(x))
#define CLR(x) FIL(x, 0)
#define NE1(x) FIL(x, -1)
#define INF(x) FIL(x, 0x3f)
typedef long long ll, i64;
ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a % b); }
ll f(ll n, ll m)
{
ll x = n;
do
if (gcd(++x, n) == 1) m--;
while (m);
return x;
}
int main()
{
ll T, k, m;
scanf("%lld", &T);
while (T--)
{
scanf("%lld%lld", &k, &m);
bool flag = true;
for (ll n = 1; n < 10000; n++)
if (((f(n, m) - n) ^ n) == k)
{
printf("%lld\n", n);
flag = false;
break;
}
if (flag) puts("-1");
}
return 0;
}