#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

const int N = 40010;

int n, m;
int p[N];

int get(int x, int y)
{
    return x * n + y;
}

int find(int x)
{
    if (p[x] != x) p[x] = find(p[x]);
    return p[x];
}

int main()
{
    cin >> n >> m;

    for (int i = 0; i < n * n; i ++ ) p[i] = i;

    int res = 0;
    for (int i = 1; i <= m; i ++ )
    {
        int x, y;
        char d;
        cin >> x >> y >> d;
        x --, y -- ;
        int a = get(x, y);//映射成一维坐标
        int b;
        if (d == 'D') b = get(x + 1, y);
        else b = get(x, y + 1);

        int pa = find(a), pb = find(b);
        if (pa == pb)//如果a,b的祖宗一样，连起来就变成了环
        {
            res = i;
            break;
        }
        p[pa] = pb;
    }

    if (!res) puts("draw");
    else cout << res << endl;

    return 0;
}