Problem Solving

What is for dinner.cpp

#include <iostream>
#include <math.h>

using namespace std;

int main() {

    long long n, m, k, r, val;
    cin >> n >> m >> k;
    long long c[m], rmn = k;
    for (int i = 0; i < m; i++)
        c[i] = pow(10,6);
    for (int i = 0; i < n; i++) {
        cin >> r >> val;
        r--;
        if (val < c[r])
            c[r] = val;
    }
    for (int i = 0; i < m; i++)
        rmn -= c[i];
    if (rmn < 0)
        cout << k;
    else
        cout << k - rmn;

    return 0;
}