cf 1519B

#include<stdio.h>

int main()
{
    int t;
    scanf("%d", &t);

    while(t--)
    {
        int n, m, k;
        scanf("%d %d %d", &n, &m, &k);
        if(n*m - 1 == k) printf("YES\n");
        else printf("NO\n");
    }
}