#include <bits/stdc++.h>
using namespace std;
const int maxn = 750;
int n, m, s;
int mchild[maxn];
int schild[maxn];
int dp[maxn][maxn][maxn];
int sol = 0;
int main(){
cin >> n >> m >> s;
for(int i = 0; i < n; i++){
cin >> mchild[i] >> schild[i];
}
for(int i = 1; i <= n; i++){
for(int j = 0; j <= m; j++){
for(int k = 0; k <= s; k++){
if(k == 0 and j == 0) continue;
dp[i][j][k] = max(dp[i-1][j][k], dp[i][j][k]);
int ssl = 0;
if(k == 0) ssl = dp[i-1][j-1][k]+mchild[i-1];
else if(j == 0) ssl = dp[i-1][j][k-1]+schild[i-1];
else ssl = max(dp[i-1][j-1][k]+mchild[i-1], dp[i-1][j][k-1]+schild[i-1]);
dp[i][j][k] = max(ssl, dp[i][j][k]);
}
}
//cout << dp[i][1][1] << '\n';
}
cout << dp[n][m][s] << '\n';
}
