#include <bits/stdc++.h>
using namespace std;
inline int read() {
int x = 0,tmp = 1;char ch = getchar();
while( ch < '0' || ch > '9' ) {if ( ch == '-' ) tmp = -1; ch = getchar();}
while( ch >= '0' && ch <= '9'){x = x * 10 + ch - '0'; ch = getchar(); }
return x * tmp;
}
int INF;
struct Point {
int to, next, w;
} edge[410000];
int head[1100], idx = 0, dis[1100], in[1100];
bool vis[1100];
inline void ade( int u, int v, int w ) {
edge[++ idx].to = v;
edge[idx].w = w;
edge[idx].next = head[u];
head[u] = idx;
}
int spfa( int _sta, int _end ) {
memset( in, 0, sizeof( in ) );
memset( vis, 0, sizeof( vis ) );
memset( dis, 127, sizeof( dis ) ); INF = dis[0];
vis[_sta] = 1; dis[_sta] = 0;
queue< int > Q;
Q.push( _sta ); in[_sta] = 1;
while( !Q.empty() ) {
int now = Q.front();
Q.pop();
vis[now] = 0;
for( int i = head[now] ; i != -1 ; i = edge[i].next ) {
int son = edge[i].to, w = edge[i].w;
if( dis[son] > dis[now] + w ) {
dis[son] = dis[now] + w;
if( !vis[son] ) {
in[son] ++;
if( in[son] > _end ) return -1;
vis[son] = 1;
Q.push( son );
}
}
}
}
if( dis[_end] == INF ) return -2;
return dis[_end];
}
int main() {
memset( head, -1, sizeof( head ) );
int N = read(), M1 = read(), M2 = read();
for( int i = 1 ; i <= M1 ; ++ i ) {
int u = read(), v = read(), w = read();
ade( u, v, w );
}
for( int i = 1 ; i <= M2 ; ++ i ) {
int u = read(), v = read(), w = read();
ade( v, u, -w );
}
for( int i = 2 ; i <= N ; ++ i ) ade( i, i - 1, 0 );
printf( "%d\n", spfa( 1, N ) );
return 0;
}
/**************************************************************
Problem: 1142
User: ARZhu
Language: C++
Result: 正确
Time:4 ms
Memory:6364 kb
****************************************************************/
