#include <stdio.h>
int main() {
	int N, A, C;
	scanf("%d",N);
	scanf("%d",A);
	scanf("%d",C);
	for (i=0;i<N;i++) {
		scanf("%d",t);
		scanf("%d",r);
		scanf("%d",m);
		if(m>2*t*C) and (A>=r) {
			A+=m;
			A-=2*t*C;
		}
	}
	printf("%d",A);
}