#include <stdio.h> int main(void) { int total, count; int sum = 0; scanf("%d", &total); scanf("%d", &count); int i; for (i = 0; i < count; i++) { int a, b; scanf("%d %d", &a, &b); sum += a * b; } if (total == sum) printf("Yes"); else printf("No"); return 0; }