#include <stdio.h>

int main() {

    int math = 0;//初始化
    int chinese = 0;
    int english = 0;
    scanf("%d %d %d", &math, &chinese, &english);//输入成绩
    int average = (math + chinese + english) / 3;//平均成绩
    if (average >= 60)//判断
    {
        printf("NO\n");
    }
    else 
    {
        printf("YES\n");
    }

    return 0;
}