C语言，不太清楚最后三个测试点为什么有错

#include <stdio.h>
int main()
{
    int s, v, m, time, go;
    scanf("%d %d", &s, &v);
    if(s%v==0)
    {
        m = s / v;
    }
    else if(s%v!=0)
    {
        m = s / v + 1;
    }
    time = m + 10;
    go = 480 - time;
    if (go % 60 >= 10)
    {
        printf("0%d:%d", go / 60, go % 60);
    }
    else if (go % 60 < 10)
    {
        printf("0%d:0%d", go / 60, go % 60);
    }
    return 0;
}