#include <cstdio>
#include <algorithm>
#define MAXN 50
#define MAXC 812
#define INF 0x3f3f3f3f
using namespace std;
int g[MAXN], y[MAXN], dp[MAXN][MAXC][MAXC], seen[MAXN][MAXC][MAXC], n, TC =0;

int sol(int idx, int yel, int green){
    if(yel <0 || green <0)
        return -INF;
    if(idx > n)
        return 0;
    if(seen[idx][yel][green] == TC)
        return dp[idx][yel][green];

    seen[idx][yel][green] = TC;
    return dp[idx][yel][green] = max(sol(idx+1, yel, green), 1+sol(idx+1, yel+y[idx], g[idx]+green));
}
int main()
{
    int a, b;
    while(scanf("%d", &n)!=EOF){
        scanf("%d %d", &a, &b);
        ++TC;
        for(int i = 1; i<=n; ++i)
            scanf("%d %d", g+i, y+i);

        printf("%d\n", sol(1, b,a));
    }
}