#include <bits/stdc++.h>
using namespace std;
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};
#define pb push_back
#define int long long
#define no "NO\n"
#define yes "YES\n"
#define ew "\n"
#define all(x) x.begin(), x.end()
#define F first
#define S second
#define float long double
#define len(x) (int)x.size()
#define macvin \
ios_base::sync_with_stdio(0); \
cin.tie(0); \
cout.tie(0);
using pii = pair<int, int>;
using ld = long double;
const int N = 2e6 + 7;
const int mod = 1e9 + 7;
const int inf = 1e18 + 7;
const int hh = 1e2 + 70;
const int MAX = 200007;
const int maxn = 1e6 + 7;
int n, k;
int q[N], a[N];
int cnt[N];
bool used[N];
void iamgoingto10of10()
{
cin >> n;
string s;
cin >> s;
int cntr = 0, cntg = 0, cnty = 0;
for (int i = 0; i < n; i++)
{
if (s[i] == 'R')
{
cntr++;
}
else if (s[i] == 'G')
{
cntg++;
}
else
{
cnty++;
}
}
if (cnty == 0 && cntg >= 1 && cntr >= 1)
{
bool ok = 0;
// cout << cntg << " " << cntr << ew;
if (n % 2 == 1)
{
if (abs(cntr - cntg) > 1)
{
ok = 0;
}
else
{
ok = 1;
}
}
else
{
if (cntr != cntg)
{
ok = 0;
}
else
{
ok = 1;
}
}
if (ok == 0)
{
cout << -1;
return;
}
int rs = 0;
for (int i = 0; i < n - 2; i++)
{
if (s[i] == s[i + 1] && s[i + 1] != s[i + 2])
{
rs++;
}
}
if (rs == 1 && n > 4)
{
cout << n << ew;
return;
}
cout << rs << ew;
return;
}
}
signed main()
{
macvin int T = 1;
// cin >> T;
while (T--)
{
iamgoingto10of10();
}
}
/*
⣿⣿⣿⣿⣿⣿⠂⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⣠⣤⣤⠤⠤⠀⠒⠶⣀⠀⠀⠀⠈⣿⣿⣿⡿⠁
⣿⣿⣿⣿⣿⡗⠈⠀⠀⠀⣠⢀⣀⠀⣀⠀⢀⡀⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠶⠚⣛⣉⠠⠀⣄⣀⠀⠀⠀⠀⠀⠀⠀⢿⣿⡿⠁⠀
⠃⠀⠀
⠀⣿⣼⡟⣿⣿⠀⢀⠢⠁⠀⣰⣜⣿⢿⣿⠿⢿⠟⢕⠢⠀⠃⠀⠀⠀⠀⠀⠀⠀⠐⠁⠈⠒⠒⠁⠀⠈⠅⠀⠀⠀⠀⠀⠀⡘⠟⢀⠀⠀
⠲⣿⢧⡃⣽⣿⠂⠀⠀⠀⠀⠉⠟⠉⠠⠈⠁⠀⠀⠀⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠺⠀⠀⠀⠀
⠀⡹⠸⣇⢸⣿⡅⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡄⠆⠀⠀⠀
⢠⡇⠀⣿⡘⢿⣧⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡇⠀⠀⠀⠀
⣼⣯⡈⠈⢯⠎⠻⡜⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡀⠀⠀
⣿⣷⣿⣆⢘⣆⠀⣷⢁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣷⠮⠁⠀⠀
⣿⣿⣿⣿⣶⣌⠦⣜⡏⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡄⠀⣀⡄⠀⠀⠀⣰⣤⡠⠂⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠐⢋⠄⠀⢀⢠
⣿⣿⣿⣿⣿⣿⣷⣎⣗⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⢛⠙⠛⡈⠀⠜⠈⠈⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡂⢠⡴⣏⢧
⣿⣿⣿⣿⣿⣿⣿⣿⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣷⢿⡱⣏⠖
⣿⣿⣿⣿⣿⣿⣿⣿⣿⡇⠀⠀⠀⠀⠀⠀⠀⠀⠠⢤⣤⣤⣤⣄⣀⣠⣀⣠⠶⠴⠦⠤⠒⠋⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⡿⣏⠷⠈⠌
⠀⠌⠙⠻⣿⣿⣿⣿⣿⣧⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢺⠟⠀⠀⠀⠀
⠀⠀⠀⠀⢉⠻⣿⣿⣿⣿⣧⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢠⠀⡈⠇⠀⠀⠀⠀
⠀⠀⠀⠀⠈⠉⠙⠻⢿⣿⣿⣷⣄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠔⠇⢠⠃⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⢠⣿⣿⣿⣿⣿⣦⡀⢀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡠⠊⠁⠀⢠⠎⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⢠⣿⣿⣿⣿⣿⢹⣿⣞⡄⡀⠄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡠⠎⠀⠀⣀⠔⠁⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⣼⣿⣿⣿⣿⣿⣈⢻⣿⣧⣗⣤⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡠⢖⡡⠔⣠⡰⠋⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⣼⣿⡏⠈⣿⡿⠁⠀⠀⠽⢿⣿⣾⣽⡷⣦⢤⡀⡄⣀⠀⡀⡀⠄⠔⣒⢱⣜⣮⡴⠚⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⣾⣿⣿⡇⠀⢿⠁⠀⠀⠀⠀⠈⠙⣿⣿⣿⣿⣯⣷⡬⣫⡀⡱⣀⣖⣼⣾⣿⠟⠋⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠻⡟⠙⡷⠀⠈⠀⠀⠀⠀⠀⠀⠀⠀⠙⠿⣿⣿⣿⣿⣷⣿⣿⣿⣿⠿⠋⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⡇⠀⠀⠀⠀⠀⠀⠀⠀⠈⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⠉⣻⣟⢿⣿⠟⣋⡀⠀⠀⠀⠀⢀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠹⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⡾⢛⣽⣴⢴⣟⢙⣿⣦⡙⠑⠓⠙⠃⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
*/
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
336 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
336 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
336 KB |
Output is correct |
2 |
Incorrect |
0 ms |
336 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
336 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |