#include <stdio.h>

int main() {
    double a, b,c;
    while (scanf("%lf %lf %lf", &a, &b,&c) != EOF) { // 注意 while 处理多个 case
        // 64 位输出请用 printf("%lld") to 
    long long a_int = (long long)(a * 1e6 + 0.5);
    long long b_int = (long long)(b * 1e6 + 0.5);
    long long c_int = (long long)(c * 1e6 + 0.5);
     if (a_int - b_int == c_int) 
        printf("YES\n");
else printf("NO");
    }
    return 0;
}