#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> PII;
const int N = 1e5 + 10;
struct edge { int x, y, c; } E[N];
vector<PII> G[N];
int n, m, q, fa[N], f[N][21], g[N][21], dep[N], D;

int findfa(int x) { return x == fa[x] ? x : fa[x] = findfa(fa[x]); }

void dfs(int x, int ff) {
    dep[x] = dep[ff] + 1;
    f[x][0] = ff;
    for (int i = 1; i <= D; i++) f[x][i] = f[f[x][i-1]][i-1];
    for (int i = 1; i <= D; i++) g[x][i] = max(g[x][i-1], g[f[x][i-1]][i-1]);
    
    for (auto [y, w] : G[x]) if (y ^ ff)
        g[y][0] = w, dfs(y, x);
}

int query(int x, int y) {
    if (findfa(x) != findfa(y)) return -1;
    if (dep[x] < dep[y]) swap(x, y);
    int ans = 0;
    for (int i = D; i >= 0; --i) if (dep[f[x][i]] >= dep[y])
        ans = max(ans, g[x][i]), x = f[x][i];
    if (x == y) return ans;
    for (int i = D; i >= 0; --i) if (f[x][i] != f[y][i])
        ans = max({ans, g[x][i], g[y][i]}), x = f[x][i], y = f[y][i];
    return ans = max({ans, g[x][0], g[y][0]});
}

int main() {
    scanf("%d%d%d", &n, &m, &q);
    for (int i = 1; i <= m; ++i) scanf("%d%d%d", &E[i].x, &E[i].y, &E[i].c);
    sort(E + 1, E + m + 1, [&](edge a, edge b) { return a.c < b.c; });
    for (int i = 1; i <= n; ++i) fa[i] = i;
    for (int i = 1; i <= m; ++i) if (findfa(E[i].x) != findfa(E[i].y)) {
        G[E[i].x].push_back({E[i].y, E[i].c});
        G[E[i].y].push_back({E[i].x, E[i].c});
        fa[findfa(E[i].x)] = findfa(E[i].y);
    }
    memset(dep, 0, sizeof(dep)); D = log2(n);
    for (int i = 1; i <= n; ++i) if (!dep[i]) dfs(i, 0);
    while (q--) {
        int s, t; scanf("%d%d", &s, &t);
        printf("%d\n", query(s, t));
    }
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
typedef pair<int,int> PII;
const int N=1e5+10;
struct edge{int x,y,c;}E[N];
vector<PII>G[N];
int n,m,q,fa[N],f[N][21],g[N][21],dep[N],D;;
int findfa(int x) { return x==fa[x] ? x : fa[x]=findfa(fa[x]); }
void dfs(int x, int ff)
{
	dep[x]=dep[ff]+1;
	f[x][0]=ff;for(int i=1;i<=D;i++)f[x][i]=f[f[x][i-1]][i-1];
	for(int i=1;i<=D;i++)g[x][i]=max(g[x][i-1],g[f[x][i-1]][i-1]);
	
	for(auto [y,w]:G[x])if(y^ff)
		g[y][0]=w,
		dfs(y,x);
}
int query(int x,int y)
{
	if(findfa(x)!=findfa(y)) return -1;
	if (dep[x]<dep[y])swap(x,y);
	int ans=0;
	for(int i=D;i>=0;--i)if(dep[f[x][i]]>=dep[y])ans=max(ans,g[x][i]),x=f[x][i];
	if(x==y) return ans;
	for(int i=D;i>=0;--i)if(f[x][i]!= f[y][i])
		ans=max({ans,g[x][i],g[y][i]}),
		x=f[x][i],y=f[y][i];
	return ans=max({ans,g[x][0],g[y][0]});
}
int main()
{
	scanf("%d%d%d",&n,&m,&q);
	for(int i=1;i<=m;++i) scanf("%d%d%d",&E[i].x,&E[i].y,&E[i].c);
	sort(E+1,E+m+1,[&](edge a,edge b){return a.c<b.c;});
	for(int i=1;i<=n;++i)fa[i]=i;
	for(int i=1;i<=m;++i)if(findfa(E[i].x)!=findfa(E[i].y))
	{
		G[E[i].x].push_back({E[i].y,E[i].c});
		G[E[i].y].push_back({E[i].x,E[i].c}); 
		fa[findfa(E[i].x)]=findfa(E[i].y);
	}
	memset(dep,0,sizeof(dep));D=log2(n);
	for(int i=1;i<=n;++i)if(!dep[i])dfs(i,0);
	while(q--)
	{
		int s,t;scanf("%d%d",&s,&t);
		printf("%d\n",query(s,t));
	}
	return 0;
}