#include <set>

#include <map>

#include <list>

#include <cmath>

#include <queue>

#include <stack>

#include <string>

#include <vector>

#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

#define debug puts("here")

#define rep(i,n) for(int i=0;i<n;i++)

#define rep1(i,n) for(int i=1;i<=n;i++)

#define REP(i,a,b) for(int i=a;i<=b;i++)

#define foreach(i,vec) for(unsigned i=0;i<vec.size();i++)

#define pb push_back

#define RD(n) scanf("%d",&n)

#define RD2(x,y) scanf("%d%d",&x,&y)

#define RD3(x,y,z) scanf("%d%d%d",&x,&y,&z)

#define RD4(x,y,z,w) scanf("%d%d%d%d",&x,&y,&z,&w)

#define All(vec) vec.begin(),vec.end()

#define MP make_pair

#define PII pair<int,int>

#define PQ priority_queue

#define cmax(x,y) x = max(x,y)

#define cmin(x,y) x = min(x,y)

#define Clear(x) memset(x,0,sizeof(x))

/*

#pragma comment(linker, "/STACK:1024000000,1024000000")

int size = 256 << 20; // 256MB

char *p = (char*)malloc(size) + size;

__asm__("movl %0, %%esp\n" :: "r"(p) );

*/

/******** program ********************/

char op;

inline void Int(int &x){

    while(!isdigit(op=getchar()));

    x = op-'0';

    while(isdigit(op=getchar()))

        x = x*10+op-'0';

}

const int MAXN = 55;

const int MAXM = 4010;

const int INF = 1e9;

int g[MAXN][MAXN];

int dis[MAXN],n,m,k;

bool bad[MAXN],use[MAXN];

int pre[MAXN];

bool dijkstra(){

    rep1(i,n)

        dis[i] = INF;

    Clear(use);

    dis[1] = 0;

    int now , MIN;

    pre[1] = 0;

    rep(q,n){

        MIN = INF;

        rep1(j,n)

            if(!bad[j]&&!use[j]&&dis[j]<MIN)

                MIN = dis[now=j];

        if(MIN==INF)

            break;

        use[now] = true;

        rep1(j,n)

            if(!bad[j]&&!use[j]){

                if(dis[j]>dis[now]+g[now][j]){

                    pre[j] = now;

                    dis[j] = dis[now]+g[now][j];

                }

            }

    }

    return dis[n]>k;

}

int ans;

void dfs(int res,int sum){

    if(sum>=ans)return;

    if( dijkstra() ){

        ans = sum;

        return;

    }

    if(!res)

        return;

    int path[MAXN]; // 得要在每次搜索时记录

    copy(pre,pre+n+1,path);

    int x = n;

    while(path[x]){

        x = path[x];

        if(x==1)continue;

        bad[x] = true;

        dfs(res-1,sum+1);

        bad[x] = false;

    }

}

int main(){

#ifndef ONLINE_JUDGE

    freopen("sum.in","r",stdin);

    //freopen("sum.out","w",stdout);

#endif

    int x,y;

    while(true){

        Int(n);Int(m);Int(k);

        if(!n&&!m&&!k)break;

        rep1(i,n)

            rep1(j,n)

                g[i][j] = INF;

        while(m--){

            Int(x);Int(y);

            g[x][y] = 1;

        }

        Clear(bad);

        ans = INF;

        dfs(n-1,0);

        printf("%d\n",ans);

    }

    return 0;

}