CodeForces 696A Launch of Collider

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<vector>
#include<map>
#include<set>
#include<queue>
#include<stack>
#include<iostream>
using namespace std;
typedef long long LL;
const double pi=acos(-1.0),eps=1e-8;
void File()
{
    freopen("D:\\in.txt","r",stdin);
    freopen("D:\\out.txt","w",stdout);
}
template <class T>
inline void read(T &x)
{
    char c = getchar(); x = 0;while(!isdigit(c)) c = getchar();
    while(isdigit(c)) { x = x * 10 + c - ‘0‘; c = getchar();  }
}

const int maxn=200010;
int n,a[maxn];
char s[maxn];

int main()
{
    scanf("%d",&n); scanf("%s",s);
    for(int i=0;i<n;i++) scanf("%d",&a[i]);
    int ans=0x7FFFFFFF;
    for(int i=0;i<n-1;i++)
        if(s[i]==‘R‘&&s[i+1]==‘L‘) ans=min(ans,(a[i+1]-a[i])/2);
    if(ans==0x7FFFFFFF) printf("-1\n");
    else printf("%d\n",ans);
    return 0;
}