#include<bits/stdc++.h>#define int long longusing namespace std;const int MAXN=1e6+5;const
int INF=0x7f7f7f7f;struct node{int to,nxt,flow;}e[MAXN];int head[MAXN],cnt=1;inline void
adde(int x,int y,int f){e[++cnt].to=y;e[cnt].flow=f;e[cnt].nxt=head[x];head[x]=cnt;}inline
void add(int x,int y,int f){adde(x,y,f);adde(y,x,0);}int n,m,s,t;int cur[MAXN],dis[MAXN];
bitset<MAXN>vis;inline bool bfs(){queue<int>q;memset(dis,-1,sizeof dis);q.push(s);dis[s]=0
;cur[s]=head[s];while(!q.empty()){int x=q.front();q.pop();for(register int i=head[x];i;i=e
[i].nxt){int y=e[i].to,f=e[i].flow;if(dis[y]==-1&&f){dis[y]=dis[x]+1;cur[y]=head[y];if(y==
t)return true;q.push(y);}}}return false;}inline int dfs(int x,int lim){if(x==t)return lim;
int f=0;for(register int i=cur[x];i&&f<lim;i=e[i].nxt){int y=e[i].to;cur[x]=i;if(dis[y]==d
is[x]+1&&e[i].flow){int w=dfs(y,min(e[i].flow,lim-f));if(!w)dis[y]=-1;e[i].flow-=w;e[i^1].
flow+=w;f+=w;}}return f;}inline int dinic(){int ans=0,f;while(bfs())while(f=dfs(s,INF))ans
+=f;return ans;}signed main(){scanf("%lld%lld%lld%lld",&n,&m,&s,&t);for(register int i=1;i
<=m;i++){int x,y,f;scanf("%lld%lld%lld",&x,&y,&f);add(x,y,f);}printf("%lld",dinic());retur
n 0;}