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| #include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define cl(x,y) memset(x,y,sizeof(x))
inline char nc(){
static char buf[100000],*l=buf,*r=buf;
return l==r&&(r=(l=buf)+fread(buf,1,100000,stdin),l==r)?EOF:*l++;
}
inline int red(){
int res=0,f=1;char ch=nc();
while (ch<'0'||'9'<ch) {if (ch=='-') f=-f;ch=nc();}
while ('0'<=ch&&ch<='9') res=res*10+ch-48,ch=nc();
return res*f;
}
const int maxn=1005,maxe=6005;
int tst,n,e;
namespace A{
int tot,son[maxe],nxt[maxe],lnk[maxn];
inline void add(int x,int y){
son[++tot]=y;nxt[tot]=lnk[x];lnk[x]=tot;
}
}
namespace B{
int tot,son[maxe],nxt[maxe],lnk[maxn],f[maxn];
inline void add(int x,int y){
son[++tot]=y;nxt[tot]=lnk[x];lnk[x]=tot;f[y]++;
}
}
int times,dfn[maxn],low[maxn],stk[maxn],to[maxn];
bool instk[maxn];
void Tarjan(int x){
using namespace A;
dfn[x]=low[x]=++times;stk[++stk[0]]=x;instk[x]=1;
for (int j=lnk[x];j;j=nxt[j])
if (!dfn[son[j]]) Tarjan(son[j]),low[x]=min(low[x],low[son[j]]);else
if (instk[son[j]]) low[x]=min(low[x],dfn[son[j]]);
if (dfn[x]==low[x]){
while (stk[stk[0]+1]!=x){
instk[stk[stk[0]]]=0;to[stk[stk[0]--]]=x;
}
}
}
int que[maxn];
bool topo(){
using namespace B;
int hed=0,til=0;
for (int i=1;i<=n;i++)
if (!f[i]&&to[i]==i) que[++til]=i;
while (hed!=til){
if (til-hed>=2) return 0;
int x=que[++hed];
for (int j=lnk[x];j;j=nxt[j]){
f[son[j]]--;
if (!f[son[j]]) que[++til]=son[j];
}
}
return 1;
}
int main(){
tst=red();
while (tst--){
n=red(),e=red();
A::tot=0;cl(A::lnk,0); B::tot=0;cl(B::lnk,0);cl(B::f,0);
for (int i=1,x,y;i<=e;i++) x=red(),y=red(),A::add(x,y);
times=0,cl(dfn,0);cl(stk,0);cl(low,0);cl(instk,0);cl(to,0);
for (int i=1;i<=n;i++)
if (!dfn[i]) Tarjan(i);
{
using namespace A;
for (int i=1;i<=n;i++)
for (int j=lnk[i];j;j=nxt[j])
if (to[i]!=to[son[j]]) B::add(to[i],to[son[j]]);
}
if (topo()) puts("I love you my love and our love save us!");else puts("Light my fire!");
}
return 0;
}
|
