Codeforces Launch of Collider

#include<bits/stdc++.h>
using namespace std;

typedef long long LL;

#define high 200010
#define inf 2147483647
#define sf scanf
#define pf printf

struct my
{
    char ch;
    LL v;
};

my ar[high];
LL br[high];

int main()
{
    LL n;
    while(~sf("%lld", &n))
    {
        getchar();

        LL i=0 , j=0 , x;
        char dir;

        for(j=1; j<=n; j++)
        {
            sf("%c", &dir);
            i++;
            ar[i].ch = dir;
        }

        i=0;

        //getchar();

        for(j=1; j<=n; j++)
        {
            sf("%lld", &x);
            i++;
            ar[i].v=x;
        }

        //for(i=0; i<n; i++) cout << ar[i].ch << " " << ar[i].v << "\n";

        LL k=1 , cnt = inf;

        for(i=1; i<=n-1; i++)
        {
            if(ar[i].ch == 'R' and ar[i+1].ch == 'L')
            {
                cnt = min(cnt, (abs(ar[i].v - ar[i+1].v)) / 2);
            }
        }

        if(cnt == inf)
        {
            cnt = -1;
        }

        pf("%lld\n", cnt);
    }

    return 0;
}