// poj3615#include<algorithm>#include<iostream>#include<cstdlib>#include<cstring>#include<cstdio>#include<cmath>#define LL long long#define inf 2147483640#define Pi acos(-1.0)#define free(a) freopen(a".in","r",stdin),freopen(a".out","w",stdout);using namespace std;inline LL getint() {	int f,x=0;char ch=getchar();	while (ch<=‘0‘ || ch>‘9‘) {if (ch==‘-‘) f=-1;else f=1;ch=getchar();}	while (ch>=‘0‘ && ch<=‘9‘) {x=x*10+ch-‘0‘;ch=getchar();}	return x*f;}const int maxn=310;int f[maxn][maxn],n,m,T;int main() {	scanf("%d%d%d",&n,&m,&T);	for (int i=1;i<=n;i++)		for (int j=1;j<=n;j++) if (i!=j) f[i][j]=inf;	for (int u,v,w,i=1;i<=m;i++) {		scanf("%d%d%d",&u,&v,&w);		f[u][v]=w;	}	for (int k=1;k<=n;k++)		for (int i=1;i<=n;i++)			for (int j=1;j<=n;j++)				f[i][j]=min(f[i][j],max(f[i][k],f[k][j]));	for (int x,y,i=1;i<=T;i++) {		scanf("%d%d",&x,&y);		if (f[x][y]==inf) puts("-1");		else printf("%d\n",f[x][y]);	}	return 0;}