cf 6a Triangle

#include <iostream>#include <cstdio>#include <algorithm>using namespace std;int main(){    int a[4];    int flag=0;    for(int i=0;i<4;i++)        scanf("%d",&a[i]);    sort(a,a+4);    if(a[0]+a[1]>a[2])        flag=1;    else if(a[1]+a[2]>a[3])        flag=1;    else if(a[0]+a[1]==a[2])        flag=2;    else if(a[0]+a[1]==a[3])        flag=2;    else if(a[0]+a[2]==a[3])        flag=2;    else if(a[1]+a[2]==a[3])        flag=2;    if(flag==1)        printf("TRIANGLE\n");    else if(flag==2)        printf("SEGMENT\n");    else        printf("IMPOSSIBLE\n");    return 0;}