#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N = 1e5 + 50;
int n, m, fa[N], r[N];
map<int, int> mp;
int ans, cnt = 0;
int find (int x) {
if (fa[x] == -1) return x;
int pre = find (fa[x]);
r[x] = (r[x] + r[fa[x]]) % 2;
return fa[x] = pre;
}
bool Union (int u, int v, int w) {
int fu = find (u);
int fv = find (v);
if (fu == fv)
return (r[v] - r[u] + 2) % 2 != w;
fa[fv] = fu;
r[fv] = (-r[v] + w + r[u] + 2) % 2;
return false;
}
signed main () {
cin >> n >> m;
memset (fa, -1, sizeof fa);
memset (r, 0, sizeof r);
ans = m;
for (int i = 1; i <= m; i++) {
int u, v;
char s[5];
cin >> u >> v >> s;
u--;
if (mp.find (u) == mp.end ()) mp[u] = ++cnt;
if (mp.find (v) == mp.end ()) mp[v] = ++cnt;
int k = (int) (s[0] == 'o');
if (ans == m && Union (mp[u], mp[v], k))
ans = i - 1;
}
mp.clear ();
cout << ans << endl;
}
#include <bits/stdc++.h>
using namespace std;
int n, m, tot, res, b[100010], fa[100010];
#define int long long
struct node {
int u, v;
string op;
} a[100010];
inline int find (int x) {
if (fa[x] == x) return x;
return fa[x] = find (fa[x]);
}
signed main () {
ios::sync_with_stdio (false);
cin.tie (nullptr), cout.tie (nullptr);
cin >> n >> m;
for (int i = 1; i <= m; i++) {
cin >> a[i].u >> a[i].v;
cin >> a[i].op;
b[++tot] = a[i].u;
b[++tot] = a[i].v;
}
sort (b + 1, b + 1 + tot);
res = unique (b + 1, b + 1 + tot) - (b + 1);
for (int i = 1; i <= m; i++) { //STL实现离散化的三部曲
a[i].u = lower_bound (b + 1, b + 1 + res, a[i].u - 1) - b;
a[i].v = lower_bound (b + 1, b + 1 + res, a[i].v) - b;
}
for (int i = 1; i <= 2 * res; i++) fa[i] = i;
for (int i = 1; i <= m; i++) {
if (a[i].op == "even"){ //如果回答是偶数个
if (find (a[i].u) == find (a[i].v + res) || find (a[i].u + res) == find (a[i].v)){ //判断奇偶性
cout << i - 1 << " "; //注意是i-1而不是i
return 0;
}
fa[find (a[i].u)] = find (a[i].v);
fa[find (a[i].u + res)] = find (a[i].v + res);
} else {
if (find (a[i].u) == find (a[i].v) || find (a[i].u + res) == find (a[i].v + res)){
cout << i - 1;
return 0;
}
fa[find (a[i].u)] = find (a[i].v + res);
fa[find (a[i].u + res)] = find (a[i].v);
}
}
cout << m << endl;
return 0;
}